diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index b92c349..b24f95f 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -5,14 +5,48 @@ on:
   push:
     branches: [main]
 
+# Minimal workflow token: the pipeline only reads repository contents
+# (checkout, frozen install, typecheck, lint, tests, build) — nothing writes
+# back, so the token is scoped to contents: read (E00-S05-T01).
+permissions:
+  contents: read
+
+# E00-S05-T01 — CI quality baseline (required PR stages).
+#
+# Every pull request runs the required quality stages in order, each gated on
+# the previous stage through `needs`:
+#
+#   1. frozen-install       — the committed lockfile installs cleanly
+#   2. typecheck            — every workspace package passes `tsc --noEmit`
+#   3. formatting-lint      — the dependency-free formatting/lint policy (`pnpm lint`)
+#   4. unit                 — deterministic unit suites (health, config, env example…)
+#   5. architecture         — static workspace/container structure and policy suites
+#   6. postgres-integration — PostgreSQL adapter suites (docker-gated real-stack
+#                             probes run where a Docker daemon is available and
+#                             skip cleanly otherwise)
+#   7. build-apps           — builds the workspace applications (apps/*: server
+#                             today, admin when E06-S01 lands) and verifies the
+#                             compiled artifact
+#
+# The stage order, the `needs` chain and the tests/ coverage are locked in by
+# tests/ci-stages.test.mjs (architecture stage). Third-party actions
+# (actions/checkout, actions/setup-node) are pinned to full commit SHAs — no
+# floating tags — and the workflow token is scoped to `contents: read`
+# (E00-S05-T01 hardening). Container/Compose smoke on main/release branches
+# and the Docker Compose baseline stack (E00-S02) stay out of scope for this
+# stage list.
+
 jobs:
+  # Stage 1 — frozen install (E00-S05-T01). Runs before every later stage: the
+  # committed lockfile must install cleanly and be up to date with the
+  # manifests before any stage proceeds.
   frozen-install:
-    name: Frozen lockfile install
+    name: Stage 1 — Frozen lockfile install (E00-S05-T01)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Install Node.js 24
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
         with:
           node-version: '24'
       - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
@@ -22,308 +56,185 @@ jobs:
       - name: Verify workspace groups
         run: pnpm -r list --depth -1
 
-  # E00-S02-T08: the static assertions of tests/secrets-not-embedded.test.mjs
-  # gate every PR (the docker-gated layer-scan probe inside the same file runs
-  # where a Docker daemon is available and skips cleanly otherwise).
-  secrets-not-embedded:
-    name: Secrets not embedded (E00-S02-T08)
+  # Stage 2 — typecheck (E00-S05-T01).
+  typecheck:
+    name: Stage 2 — Typecheck (E00-S05-T01)
+    needs: frozen-install
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Install Node.js 24
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
         with:
           node-version: '24'
-      - name: Run secrets-not-embedded test suite
+      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
+        run: corepack enable
+      - name: Install dependencies (frozen lockfile)
+        run: pnpm install --frozen-lockfile
+      - name: Typecheck every workspace package
+        run: pnpm typecheck
+
+  # Stage 3 — formatting/lint policy (E00-S05-T01). `pnpm lint` runs the
+  # dependency-free formatting-policy suite (tests/formatting-policy.test.mjs):
+  # LF line endings, no BOM, no trailing whitespace, no tab indentation, final
+  # newline, and valid JSON with 2-space indentation and no duplicate keys.
+  formatting-lint:
+    name: Stage 3 — Formatting/lint policy (E00-S05-T01)
+    needs: typecheck
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Install Node.js 24
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
+        with:
+          node-version: '24'
+      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
+        run: corepack enable
+      - name: Install dependencies (frozen lockfile)
+        run: pnpm install --frozen-lockfile
+      - name: Run the formatting/lint policy
+        run: pnpm lint
+
+  # Stage 4 — unit tests (E00-S05-T01). Deterministic suites that gate every
+  # PR without external services: the app health endpoint, the secrets scan
+  # and the configuration service suites (schema, startup error, log
+  # redaction, env adapter, .env.example). The config suites boot the
+  # committed server, so the config and database-postgres packages are built
+  # first.
+  unit:
+    name: Stage 4 — Unit tests (E00-S05-T01)
+    needs: formatting-lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Install Node.js 24
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
+        with:
+          node-version: '24'
+      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
+        run: corepack enable
+      - name: Install dependencies (frozen lockfile)
+        run: pnpm install --frozen-lockfile
+      - name: Build the config and database-postgres packages (the probes boot the committed server which imports them)
+        run: pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build
+      - name: Run the health-endpoint unit suite
+        run: node --test tests/health-endpoint.test.mjs
+      - name: Run the secrets-not-embedded unit suite
         run: node --test tests/secrets-not-embedded.test.mjs
-
-  # E00-S03-T02: the static assertions of tests/database-postgres-imports.test.mjs
-  # gate every PR — the scan proves pg/Kysely imports live only in
-  # packages/database-postgres and the mutation probes prove the scan catches
-  # a driver import injected into any other package.
-  database-postgres-imports:
-    name: Database-postgres import isolation (E00-S03-T02)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Run database-postgres import isolation suite
-        run: node --test tests/database-postgres-imports.test.mjs
-
-  # E00-S03-T03: the static assertions of tests/database-postgres-ledger.test.mjs
-  # gate every PR — the suite locks in the migration ledger (schema_migrations
-  # table DDL, idempotent parameterized record, driver-boundary re-export)
-  # with mutation probes, and the docker-gated real-stack probe (migrate an
-  # empty database and confirm the ledger exists) runs where a Docker daemon
-  # is available and skips cleanly otherwise. The job installs the frozen
-  # workspace because the real-stack probe executes the committed ledger
-  # module from the host (it imports `pg` through the package's own links).
-  database-postgres-ledger:
-    name: Migration ledger (E00-S03-T03)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
-        run: corepack enable
-      - name: Install dependencies (frozen lockfile)
-        run: pnpm install --frozen-lockfile
-      - name: Run migration ledger test suite
-        run: node --test tests/database-postgres-ledger.test.mjs
-
-  # E00-S03-T04: the static assertions of tests/database-postgres-lock.test.mjs
-  # gate every PR — the suite locks in the migration advisory lock (session-
-  # scoped pg_advisory_lock/pg_try_advisory_lock over a stable keyed hash on a
-  # dedicated connection, re-entrant-safe in-flight acquire so concurrent
-  # acquire() calls share one connection, driver-boundary re-export) with
-  # mutation probes, and the docker-gated real-stack concurrent probe (a
-  # second runner waits or fails while the first holds the lock; concurrent
-  # acquire() checks out exactly one connection; the lock releases when the
-  # holding session ends) runs where a Docker daemon is available and skips
-  # cleanly otherwise. The job installs the frozen workspace because the
-  # real-stack probe executes the committed lock module from the host (it
-  # imports `pg` through the package's own links).
-  database-postgres-lock:
-    name: Migration advisory lock (E00-S03-T04)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
-        run: corepack enable
-      - name: Install dependencies (frozen lockfile)
-        run: pnpm install --frozen-lockfile
-      - name: Run migration advisory lock test suite
-        run: node --test tests/database-postgres-lock.test.mjs
-
-  # E00-S03-T05: the static assertions of tests/database-postgres-diagnostic.test.mjs
-  # gate every PR — the suite locks in the migration failure diagnostic (a
-  # structured MigrationFailedError whose diagnostic identifies the failing
-  # migration, the failure phase, the underlying cause, and the applied/pending
-  # ledger state, serializable via toJSON) with mutation probes, and a
-  # deterministic stub-pool behavioral probe (intentionally failing migration
-  # fixture -> structured diagnostic naming the failing migration) runs on
-  # Node 24; the docker-gated real-stack probe (the issue's test plan: "run an
-  # intentionally failing migration fixture and confirm the diagnostic") runs
-  # where a Docker daemon is available and skips cleanly otherwise. The job
-  # installs the frozen workspace because the probes execute the committed
-  # runner module from the host (it imports `pg` through the package's own
-  # links).
-  database-postgres-diagnostic:
-    name: Migration failure diagnostic (E00-S03-T05)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
-        run: corepack enable
-      - name: Install dependencies (frozen lockfile)
-        run: pnpm install --frozen-lockfile
-      - name: Run migration failure diagnostic test suite
-        run: node --test tests/database-postgres-diagnostic.test.mjs
-
-  # E00-S03-T06: the static assertions of tests/app-readiness.test.mjs gate
-  # every PR — the suite locks in the readiness gate (the app answers
-  # GET /health with 503 {"status":"not ready"} until the startup migration
-  # run completes, then 200 {"status":"ok"}) with mutation probes, the
-  # deterministic probes (boot the committed server: no DATABASE_URL ->
-  # ready immediately; unreachable DATABASE_URL -> stays not-ready) run on
-  # Node 24, and the docker-gated real-stack probe (the issue's test plan:
-  # "start with pending migrations and confirm readiness waits" — the app's
-  # migration run is blocked behind a held ACCESS EXCLUSIVE lock on the
-  # migration ledger, /health stays not-ready, then flips ready once the lock
-  # releases) runs where a Docker daemon is available and skips cleanly
-  # otherwise. The job installs the frozen workspace and builds the config
-  # and database-postgres packages because the probes boot the committed
-  # server from the host (it imports @personal-blog/config and
-  # @personal-blog/database-postgres through the packages' own links; the
-  # required EPPP_SESSION_SECRET is provided by the probe's boot env).
-  app-readiness:
-    name: App readiness after migrations (E00-S03-T06)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
-        run: corepack enable
-      - name: Install dependencies (frozen lockfile)
-        run: pnpm install --frozen-lockfile
-      - name: Build the config and database-postgres packages (the probes boot the committed server which imports them)
-        run: pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build
-      - name: Run app readiness test suite
-        run: node --test tests/app-readiness.test.mjs
-
-  # E00-S04-T02: the static assertions of tests/config-startup-error.test.mjs
-  # gate every PR — the suite locks in the field-specific startup error (a
-  # missing required setting fails startup with an error naming the missing
-  # field: packages/config's MissingRequiredSettingError/assertValidConfig,
-  # wired into the committed server before it binds) with mutation probes, and
-  # the deterministic probes execute the issue's test plan ("start with a
-  # missing required field and confirm the error names it"): booting the
-  # committed server without EPPP_SESSION_SECRET exits non-zero naming
-  # sessionSecret, while a valid secret boots to GET /health 200. The job
-  # installs the frozen workspace and builds the config and database-postgres
-  # packages because the probes boot the committed server which imports them.
-  config-startup-error:
-    name: Field-specific startup errors (E00-S04-T02)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
-        run: corepack enable
-      - name: Install dependencies (frozen lockfile)
-        run: pnpm install --frozen-lockfile
-      - name: Build the config and database-postgres packages (the probes boot the committed server which imports them)
-        run: pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build
-      - name: Run config startup error test suite
-        run: node --test tests/config-startup-error.test.mjs
-
-  # E00-S04-T03: the static assertions of tests/config-log-redaction.test.mjs
-  # gate every PR — the suite locks in automatic secret redaction from logs
-  # (packages/config's redactConfig/redactText + the server's redacting
-  # logger: every log line is scrubbed of the config's secret values) with
-  # mutation probes, and the deterministic probes execute the issue's test
-  # plan ("log configuration and confirm secret values are redacted"):
-  # booting the committed server logs its resolved configuration with the
-  # secret values replaced by [REDACTED], and no secret value appears in the
-  # log output. The job installs the frozen workspace and builds the config
-  # and database-postgres packages because the probes boot the committed
-  # server which imports them.
-  config-log-redaction:
-    name: Secret redaction from logs (E00-S04-T03)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
-        run: corepack enable
-      - name: Install dependencies (frozen lockfile)
-        run: pnpm install --frozen-lockfile
-      - name: Build the config and database-postgres packages (the probes boot the committed server which imports them)
-        run: pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build
-      - name: Run config log redaction test suite
-        run: node --test tests/config-log-redaction.test.mjs
-
-  # E00-S04-T04: the static assertions of tests/config-env-adapter.test.mjs
-  # gate every PR — the suite locks in the environment adapter (packages/config
-  # is the single owner of process.env reads; the server and every other module
-  # read no process.env, all settings flow through loadConfigFromEnv into the
-  # validated config) with a comment-stripped workspace scan, mutation probes
-  # (injecting a direct process.env read into any other module fails the scan),
-  # a deterministic boundary probe (full env mapping, defaults, bad-PORT
-  # fallback, HOST validated as hostname/IP with invalid values throwing a
-  # field-specific startup error, missing required secret ->
-  # MissingRequiredSettingError) and server-boot probes (a PORT/HOST override
-  # shows up in the resolved configuration; HOST=127.0.0.1 binds loopback only
-  # and the startup log reflects the actual bind; an invalid HOST fails startup
-  # naming the field without echoing the raw value; a missing required secret
-  # still fails startup). The job installs the frozen workspace and builds the
-  # config and database-postgres packages because the probes boot the committed
-  # server which imports them.
-  config-env-adapter:
-    name: Env adapter owns process.env (E00-S04-T04)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
-        run: corepack enable
-      - name: Install dependencies (frozen lockfile)
-        run: pnpm install --frozen-lockfile
-      - name: Build the config and database-postgres packages (the probes boot the committed server which imports them)
-        run: pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build
-      - name: Run config env adapter test suite
-        run: node --test tests/config-env-adapter.test.mjs
-
-  # E00-S04-T01: the static assertions of tests/config-schema.test.mjs gate
-  # every PR — the suite locks in the TypeBox/Ajv configuration schema
-  # (packages/config, golden-tuple pins @sinclair/typebox@0.34.52 +
-  # ajv@8.20.0) with mutation probes, and the deterministic probe executes
-  # the issue's test plan ("validate a full config against the TypeBox/Ajv
-  # schema") against the committed schema through Ajv. The job installs the
-  # frozen workspace and builds the config package because the probe also
-  # exercises the compiled package boundary (@personal-blog/config) exactly
-  # as the later configuration adapter will consume it.
-  config-schema:
-    name: TypeBox/Ajv config schema (E00-S04-T01)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
-        run: corepack enable
-      - name: Install dependencies (frozen lockfile)
-        run: pnpm install --frozen-lockfile
-      - name: Build the config package (the probe exercises the compiled package boundary)
-        run: pnpm --filter @personal-blog/config build
-      - name: Run config schema test suite
+      - name: Run the config-schema unit suite
         run: node --test tests/config-schema.test.mjs
-
-  # E00-S04-T05: the static assertions of tests/env-example.test.mjs gate every
-  # PR — the suite locks in the committed `.env.example` template: it exists at
-  # the repo root, is un-ignored in .gitignore (real `.env` files stay ignored
-  # while the example is tracked), documents every configuration environment
-  # source (HOST/PORT/DATABASE_URL/EPPP_SESSION_SECRET), and contains
-  # placeholder values only — no credential URI, no long secret-looking value,
-  # and no compose default credential — with mutation probes proving the
-  # assertions are non-vacuous. It also locks the fail-closed EPPP_SESSION_SECRET
-  # placeholder (shorter than the schema's 32-character minimum), builds the
-  # secret-shaped probe at runtime so the branch stays gitleaks-clean, and
-  # masks raw values in assertion messages. The test needs no dependencies, so
-  # the job only installs Node.
-  env-example:
-    name: .env.example placeholders only (E00-S04-T05)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Node.js 24
-        uses: actions/setup-node@v4
-        with:
-          node-version: '24'
-      - name: Run .env.example test suite
+      - name: Run the config-startup-error unit suite
+        run: node --test tests/config-startup-error.test.mjs
+      - name: Run the config-log-redaction unit suite
+        run: node --test tests/config-log-redaction.test.mjs
+      - name: Run the config-env-adapter unit suite
+        run: node --test tests/config-env-adapter.test.mjs
+      - name: Run the env-example unit suite
         run: node --test tests/env-example.test.mjs
 
-  # E00-S03-T01: the static assertions of tests/compose-config.test.mjs (db
-  # image pinned to postgres:18.6-bookworm, health gate, volume persistence,
-  # build platforms) gate every PR (the docker-gated real-stack probes inside
-  # the same file run where a Docker daemon is available and skip cleanly
-  # otherwise).
-  compose-config:
-    name: Compose config (E00-S03-T01)
+  # Stage 5 — architecture tests (E00-S05-T01). Static structure and policy
+  # suites: dependency boundaries, workspace layout/configuration, strict
+  # TypeScript base, engine/TypeScript pins, root commands, frozen-install
+  # clean clone, container definition structure, and the CI baseline itself.
+  architecture:
+    name: Stage 5 — Architecture tests (E00-S05-T01)
+    needs: unit
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Install Node.js 24
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
         with:
           node-version: '24'
-      - name: Run compose-config test suite
+      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
+        run: corepack enable
+      - name: Install dependencies (frozen lockfile)
+        run: pnpm install --frozen-lockfile
+      - name: Build the config and database-postgres packages (strict-tsconfig typechecks apps/server which imports them)
+        run: pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build
+      - name: Run the architecture-import suite
+        run: node --test tests/architecture-import.test.mjs
+      - name: Run the no-core-extension-imports suite
+        run: node --test tests/no-core-extension-imports.test.mjs
+      - name: Run the workspace-layout suite
+        run: node --test tests/workspace-layout.test.mjs
+      - name: Run the workspace-config suite
+        run: node --test tests/workspace-config.test.mjs
+      - name: Run the strict-tsconfig suite
+        run: node --test tests/strict-tsconfig.test.mjs
+      - name: Run the typescript-pin suite
+        run: node --test tests/typescript-pin.test.mjs
+      - name: Run the node-engine suite
+        run: node --test tests/node-engine.test.mjs
+      - name: Run the frozen-install suite
+        run: node --test tests/frozen-install.test.mjs
+      - name: Run the root-commands suite
+        run: node --test tests/root-commands.test.mjs
+      - name: Run the compose-config suite
         run: node --test tests/compose-config.test.mjs
+      - name: Run the build-targets suite
+        run: node --test tests/build-targets.test.mjs
+      - name: Run the non-root-user suite
+        run: node --test tests/non-root-user.test.mjs
+      - name: Run the readonly-rootfs suite
+        run: node --test tests/readonly-rootfs.test.mjs
+      - name: Run the database-postgres-imports suite
+        run: node --test tests/database-postgres-imports.test.mjs
+      - name: Run the ci-stages baseline suite
+        run: node --test tests/ci-stages.test.mjs
+
+  # Stage 6 — PostgreSQL integration tests (E00-S05-T01). The PostgreSQL
+  # adapter suites (migration ledger, advisory lock, failure diagnostic) and
+  # the app readiness suite: their docker-gated real-stack probes (migrate an
+  # empty database, hold/release the advisory lock, readiness waits on the
+  # startup migration run) run where a Docker daemon is available and skip
+  # cleanly otherwise; the static and deterministic probes always gate. The
+  # app-readiness probes boot the committed server, so the config and
+  # database-postgres packages are built first.
+  postgres-integration:
+    name: Stage 6 — PostgreSQL integration tests (E00-S05-T01)
+    needs: architecture
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Install Node.js 24
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
+        with:
+          node-version: '24'
+      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
+        run: corepack enable
+      - name: Install dependencies (frozen lockfile)
+        run: pnpm install --frozen-lockfile
+      - name: Build the config and database-postgres packages (the probes boot the committed server which imports them)
+        run: pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build
+      - name: Run the database-postgres-ledger suite
+        run: node --test tests/database-postgres-ledger.test.mjs
+      - name: Run the database-postgres-lock suite
+        run: node --test tests/database-postgres-lock.test.mjs
+      - name: Run the database-postgres-diagnostic suite
+        run: node --test tests/database-postgres-diagnostic.test.mjs
+      - name: Run the app-readiness suite
+        run: node --test tests/app-readiness.test.mjs
+
+  # Stage 7 — build the applications (E00-S05-T01). Builds every workspace
+  # application under apps/ (apps/server today; apps/admin when E06-S01 lands
+  # — the pnpm apps-group glob picks it up automatically) and verifies the
+  # compiled server artifact.
+  build-apps:
+    name: Stage 7 — Build the admin and server applications (E00-S05-T01)
+    needs: postgres-integration
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Install Node.js 24
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
+        with:
+          node-version: '24'
+      - name: Enable pnpm (corepack, pinned to 11.23.0 via packageManager)
+        run: corepack enable
+      - name: Install dependencies (frozen lockfile)
+        run: pnpm install --frozen-lockfile
+      - name: Build the workspace applications (apps/* — server today, admin when E06-S01 lands)
+        run: pnpm --filter "./apps/**" run build
+      - name: Verify the compiled server application artifact
+        run: test -f apps/server/dist/index.js
diff --git a/docs/development/non-container.md b/docs/development/non-container.md
index f85c1a5..d172635 100644
--- a/docs/development/non-container.md
+++ b/docs/development/non-container.md
@@ -143,11 +143,22 @@ node <package-dir>/dist/index.js   # e.g. node packages/core/dist/index.js
 
 ```sh
 pnpm test
+pnpm lint
 ```
 
-`pnpm test` runs the `node:test` suites under `tests/` (currently
-`tests/architecture-import.test.mjs`, 10 tests) with zero extra dependencies.
-This is also the suite that enforces the dependency-boundary rule.
+`pnpm test` runs the `node:test` suites under `tests/` with zero extra
+dependencies (this is also the suite that enforces the dependency-boundary
+rule). `pnpm lint` runs the formatting/lint policy suite
+(`tests/formatting-policy.test.mjs`): every tracked text file must use LF
+line endings, no BOM, no trailing whitespace, no tab indentation and exactly
+one final newline; JSON files must additionally parse, carry no duplicate
+keys and use 2-space indentation.
+
+Pull requests run these checks as CI stages, in order — frozen lockfile
+install → typecheck → formatting/lint → unit → architecture → PostgreSQL
+integration → build of the applications (E00-S05-T01); the stage order,
+the `needs` chain and the `tests/` coverage are locked in by
+`tests/ci-stages.test.mjs`.
 
 ## Smoke check from a clean clone
 
@@ -157,7 +168,8 @@ corepack enable
 pnpm install --frozen-lockfile   # exit 0, lockfile untouched
 pnpm build                       # 5/5 packages emit dist/, exit 0
 pnpm typecheck                   # 5/5 packages pass --noEmit, exit 0
-pnpm test                        # 10/10 pass, exit 0
+pnpm lint                        # formatting/lint policy passes, exit 0
+pnpm test                        # all node:test suites pass, exit 0
 pnpm --filter @personal-blog/server start   # requires EPPP_SESSION_SECRET (see [Run](#run)); serves GET /health on port 3000, stays up
 ```
 
diff --git a/package.json b/package.json
index 8b9a001..f5a4b48 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
   },
   "scripts": {
     "build": "pnpm -r run build",
+    "lint": "node --test tests/formatting-policy.test.mjs",
     "test": "node --test \"tests/**/*.test.mjs\"",
     "typecheck": "pnpm -r run typecheck"
   },
diff --git a/tests/ci-stages.test.mjs b/tests/ci-stages.test.mjs
new file mode 100644
index 0000000..0103250
--- /dev/null
+++ b/tests/ci-stages.test.mjs
@@ -0,0 +1,370 @@
+/**
+ * CI quality baseline test — locks in the [E00-S05-T01] required PR stages of
+ * the committed workflow (`.gitea/workflows/ci.yml`).
+ *
+ * The baseline (issue #187 acceptance criteria):
+ *   - "CI runs frozen install before later stages" → `frozen-install` is the
+ *     first job and every later stage declares `needs` on its predecessor, so
+ *     the pipeline runs the required stages strictly in order and nothing
+ *     proceeds past a failed stage.
+ *   - "CI runs typecheck, formatting/lint, unit, architecture and PostgreSQL
+ *     integration tests" → the five stage jobs exist with the expected
+ *     commands: `pnpm typecheck`, `pnpm lint`, and the unit / architecture /
+ *     postgres-integration `node --test` suite runs.
+ *   - "CI builds the admin and server applications" → the `build-apps` stage
+ *     compiles the whole apps group (`./apps/**` — apps/server today, the
+ *     admin app when E06-S01 lands) and verifies the compiled server
+ *     artifact.
+ *   - "CI workflow pins third-party actions (actions/checkout,
+ *     actions/setup-node) to full commit SHAs, not floating tags" → every
+ *     `uses:` ref is a 40-char commit SHA pinned to the committed
+ *     PINNED_ACTIONS values — no `@v4`-style floating tags.
+ *   - "CI workflow declares minimal permissions (`permissions: contents:
+ *     read`) at the workflow level" → the workflow declares a top-level
+ *     `permissions:` block granting exactly `contents: read`.
+ *   - every committed test suite under tests/ is wired into exactly one stage
+ *     (`pnpm lint` runs the formatting-policy suite; every other suite is
+ *     named by a `node --test` run in the unit, architecture or
+ *     postgres-integration stage).
+ *
+ * Mutation probes prove the assertions are non-vacuous: removing a stage,
+ * breaking the `needs` chain, or dropping a suite from its stage all fail.
+ *
+ * Run: `node --test tests/ci-stages.test.mjs`
+ * (node:test — built into Node >= 18; no dependencies, lockfile untouched.)
+ */
+
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync, readdirSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const REPO_ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
+
+const read = (relPath) => readFileSync(path.join(REPO_ROOT, relPath), 'utf8');
+
+/** The workflow file under test. */
+const WORKFLOW = '.gitea/workflows/ci.yml';
+
+/** The required PR stages, in the order the pipeline must run them. */
+const REQUIRED_STAGES = [
+  'frozen-install',
+  'typecheck',
+  'formatting-lint',
+  'unit',
+  'architecture',
+  'postgres-integration',
+  'build-apps',
+];
+
+/** The root lint command the formatting-lint stage must run. */
+const LINT_SCRIPT = 'node --test tests/formatting-policy.test.mjs';
+
+/**
+ * The third-party actions the workflow may use, pinned to the full commit
+ * SHA of a released version (E00-S05-T01 hardening). Updating a pin means
+ * updating this table and the workflow together, in the same PR.
+ */
+const PINNED_ACTIONS = {
+  'actions/checkout': '11bd71901bbe5b1630ceea73d27597364c9af683', // v4.2.2
+  'actions/setup-node': '1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a', // v4.2.0
+};
+
+/**
+ * Parses the workflow's `jobs:` section (the committed file is 2-space
+ * indented YAML) into `{ order, jobs }` where `order` lists job keys in
+ * document order and each job carries its `needs` value and `run:` commands.
+ * Comments and blank lines are skipped; unknown keys under a job are ignored.
+ */
+function parseWorkflowJobs(yamlText) {
+  const lines = yamlText.split('\n');
+  const jobsIndex = lines.findIndex((line) => line === 'jobs:');
+  assert.ok(jobsIndex >= 0, 'the workflow must declare a top-level jobs: section');
+
+  const order = [];
+  const jobs = {};
+  let current = null;
+
+  for (let i = jobsIndex + 1; i < lines.length; i++) {
+    const line = lines[i];
+    const trimmed = line.trim();
+    if (trimmed === '' || trimmed.startsWith('#')) continue;
+    const indent = line.length - line.trimStart().length;
+    if (indent === 2) {
+      const key = /^([A-Za-z0-9_-]+):/.exec(trimmed);
+      assert.ok(key, `unexpected jobs: entry at indent 2: "${line}"`);
+      current = key[1];
+      order.push(current);
+      jobs[current] = { needs: null, runs: [] };
+      continue;
+    }
+    if (current && indent > 2) {
+      const needs = /^needs:\s*(.+)$/.exec(trimmed);
+      if (needs) jobs[current].needs = needs[1].trim().replace(/^\[|\]$/g, '');
+      const run = /^run:\s*(.+)$/.exec(trimmed);
+      if (run) jobs[current].runs.push(run[1].trim());
+    }
+  }
+
+  return { order, jobs };
+}
+
+/** Extracts the tests/*.test.mjs suite names named by `node --test` runs. */
+function suitesNamedInRuns(runs) {
+  const out = [];
+  for (const run of runs) {
+    for (const token of run.split(/\s+/)) {
+      if (token.startsWith('tests/') && token.endsWith('.test.mjs')) {
+        out.push(token.slice('tests/'.length));
+      }
+    }
+  }
+  return out;
+}
+
+/** Extracts the `uses:` refs from the workflow, e.g. "actions/checkout@<sha>". */
+function usesRefs(yamlText) {
+  const refs = [];
+  for (const line of yamlText.split('\n')) {
+    // `uses:` appears either as a bare key or as a sequence item ("- uses:").
+    const match = /^\s*(?:-\s+)?uses:\s*(\S+)/.exec(line);
+    if (match) refs.push(match[1]);
+  }
+  return refs;
+}
+
+/**
+ * Asserts the E00-S05-T01 hardening criteria: every third-party `uses:` ref
+ * is pinned to a full 40-char commit SHA (exactly the committed PINNED_ACTIONS
+ * values — no floating tags) and the workflow declares `permissions:
+ * contents: read` at the top level. Throws an AssertionError describing the
+ * first violated invariant.
+ */
+function assertHardening(yamlText) {
+  const refs = usesRefs(yamlText);
+  assert.ok(refs.length > 0, 'the workflow must use at least one third-party action');
+  for (const ref of refs) {
+    const match = /^([\w.-]+\/[\w.-]+)@([0-9a-f]{40})$/.exec(ref);
+    assert.ok(
+      match,
+      `every third-party action must be pinned to a full 40-char commit SHA, not a floating tag (got "${ref}")`,
+    );
+    assert.ok(
+      Object.hasOwn(PINNED_ACTIONS, match[1]),
+      `unexpected third-party action "${match[1]}" — add it to the PINNED_ACTIONS policy table if it is approved`,
+    );
+    assert.equal(
+      match[2],
+      PINNED_ACTIONS[match[1]],
+      `"${match[1]}" must be pinned to the committed full commit SHA ${PINNED_ACTIONS[match[1]]} (got ${match[2]})`,
+    );
+  }
+  for (const action of Object.keys(PINNED_ACTIONS)) {
+    assert.ok(
+      refs.some((ref) => ref.startsWith(`${action}@`)),
+      `the workflow must use "${action}" pinned to a full commit SHA`,
+    );
+  }
+  assert.match(
+    yamlText,
+    /^permissions:\n[ \t]+contents: read$/m,
+    'the workflow must declare a top-level "permissions: contents: read" block',
+  );
+}
+
+/**
+ * Asserts the whole E00-S05-T01 baseline for a parsed workflow. Throws an
+ * AssertionError describing the first violated invariant.
+ */
+function assertBaseline({ order, jobs }) {
+  // Every required stage exists.
+  for (const stage of REQUIRED_STAGES) {
+    assert.ok(jobs[stage], `required CI stage "${stage}" is missing from the workflow`);
+  }
+
+  // The required stages run in order (their relative order is preserved).
+  const present = order.filter((name) => REQUIRED_STAGES.includes(name));
+  assert.deepEqual(
+    present,
+    REQUIRED_STAGES,
+    `the required CI stages must run in order: ${REQUIRED_STAGES.join(' -> ')}`,
+  );
+
+  // Frozen install runs before later stages: every later stage gates on its
+  // predecessor, so the pipeline is strictly ordered.
+  for (let i = 1; i < REQUIRED_STAGES.length; i++) {
+    assert.equal(
+      jobs[REQUIRED_STAGES[i]].needs,
+      REQUIRED_STAGES[i - 1],
+      `stage "${REQUIRED_STAGES[i]}" must gate on the previous stage "${REQUIRED_STAGES[i - 1]}"`,
+    );
+  }
+
+  // Stage commands.
+  assert.ok(
+    jobs['frozen-install'].runs.some((run) => run.includes('pnpm install --frozen-lockfile')),
+    'frozen-install must run the frozen lockfile install',
+  );
+  assert.ok(
+    jobs['typecheck'].runs.some((run) => run.includes('pnpm typecheck')),
+    'the typecheck stage must run pnpm typecheck',
+  );
+  assert.ok(
+    jobs['formatting-lint'].runs.some((run) => run.includes('pnpm lint')),
+    'the formatting-lint stage must run pnpm lint',
+  );
+
+  // The build stage compiles the apps group and verifies the server artifact.
+  const buildRuns = jobs['build-apps'].runs;
+  assert.ok(
+    buildRuns.some((run) => run.includes('run build') && run.includes('./apps/**')),
+    'build-apps must build the apps group (pnpm --filter "./apps/**" run build)',
+  );
+  assert.ok(
+    buildRuns.some((run) => run.includes('apps/server/dist/index.js')),
+    'build-apps must verify the compiled server application artifact',
+  );
+
+  // Every committed test suite is wired into exactly one stage.
+  const staged = [
+    ...suitesNamedInRuns(jobs['unit'].runs),
+    ...suitesNamedInRuns(jobs['architecture'].runs),
+    ...suitesNamedInRuns(jobs['postgres-integration'].runs),
+  ];
+  const allSuites = readdirSync(path.join(REPO_ROOT, 'tests'))
+    .filter((file) => file.endsWith('.test.mjs'))
+    .sort();
+  // The formatting-policy suite is run by the formatting-lint stage via the
+  // root lint script rather than by a node --test run in a test stage.
+  const expected = allSuites.filter((file) => file !== 'formatting-policy.test.mjs');
+  assert.equal(
+    staged.length,
+    expected.length,
+    'each test suite must be wired into exactly one CI stage run ' +
+      `(staged: ${staged.join(', ')}; expected: ${expected.join(', ')})`,
+  );
+  assert.deepEqual(
+    [...new Set(staged)].sort(),
+    expected,
+    'every committed test suite must be wired into exactly one CI stage ' +
+      `(staged: ${staged.join(', ')}; expected: ${expected.join(', ')})`,
+  );
+}
+
+/** Removes the whole `  <jobName>:` block from a workflow text (probe helper). */
+function removeJobBlock(yamlText, jobName) {
+  const lines = yamlText.split('\n');
+  const start = lines.findIndex((line) => line === `  ${jobName}:`);
+  assert.ok(start >= 0, `job ${jobName} must exist in the workflow text`);
+  let end = lines.length;
+  for (let i = start + 1; i < lines.length; i++) {
+    const trimmed = lines[i].trim();
+    if (
+      trimmed !== '' &&
+      !trimmed.startsWith('#') &&
+      lines[i].length - lines[i].trimStart().length === 2 &&
+      /^[A-Za-z0-9_-]+:/.test(trimmed)
+    ) {
+      end = i;
+      break;
+    }
+  }
+  return [...lines.slice(0, start), ...lines.slice(end)].join('\n');
+}
+
+// ---------------------------------------------------------------------------
+// Real-workflow baseline
+// ---------------------------------------------------------------------------
+
+test('the committed CI workflow runs the required PR stages in order', () => {
+  assertBaseline(parseWorkflowJobs(read(WORKFLOW)));
+});
+
+test('the workflow triggers on pull requests and pushes to main', () => {
+  const text = read(WORKFLOW);
+  assert.match(text, /^on:$/m, 'the workflow must declare an on: trigger block');
+  assert.match(text, /pull_request:/, 'PRs must trigger the CI workflow');
+  assert.match(text, /push:/, 'pushes must trigger the CI workflow');
+  assert.match(text, /branches:\s*\[main\]/, 'the push trigger must cover main');
+});
+
+test('the root lint script runs the formatting-policy suite', () => {
+  const scripts = JSON.parse(read('package.json')).scripts ?? {};
+  assert.equal(
+    scripts.lint,
+    LINT_SCRIPT,
+    `root package.json must declare scripts.lint exactly as "${LINT_SCRIPT}"`,
+  );
+});
+
+test('the workflow pins third-party actions to full commit SHAs and declares minimal permissions', () => {
+  assertHardening(read(WORKFLOW));
+});
+
+// ---------------------------------------------------------------------------
+// Mutation probes — the baseline assertions are non-vacuous
+// ---------------------------------------------------------------------------
+
+test('removing a required stage fails the baseline (mutation probe)', () => {
+  const mutated = removeJobBlock(read(WORKFLOW), 'unit');
+  assert.throws(() => assertBaseline(parseWorkflowJobs(mutated)), /required CI stage "unit"/);
+});
+
+test('breaking the needs chain fails the baseline (mutation probe)', () => {
+  const text = read(WORKFLOW);
+  const mutated = text.replace('needs: formatting-lint', 'needs: typecheck');
+  assert.notEqual(mutated, text, 'the probe must mutate the workflow');
+  assert.throws(
+    () => assertBaseline(parseWorkflowJobs(mutated)),
+    /must gate on the previous stage/,
+  );
+});
+
+test('dropping a suite from its stage fails the coverage assertion (mutation probe)', () => {
+  const text = read(WORKFLOW);
+  const mutated = text.replace('tests/config-schema.test.mjs', '');
+  assert.notEqual(mutated, text, 'the probe must mutate the workflow');
+  assert.throws(
+    () => assertBaseline(parseWorkflowJobs(mutated)),
+    /must be wired into exactly one CI stage/,
+  );
+});
+
+test('reordering the stages fails the baseline (mutation probe)', () => {
+  const text = read(WORKFLOW);
+  // Swap the typecheck and formatting-lint job blocks so their document order
+  // no longer matches the required stage order.
+  const typecheckBlock = text.slice(text.indexOf('  typecheck:'), text.indexOf('  formatting-lint:'));
+  const lintBlock = text.slice(text.indexOf('  formatting-lint:'), text.indexOf('  unit:'));
+  const mutated = text.replace(typecheckBlock + lintBlock, lintBlock + typecheckBlock);
+  assert.notEqual(mutated, text, 'the probe must mutate the workflow');
+  assert.throws(() => assertBaseline(parseWorkflowJobs(mutated)), /must run in order/);
+});
+
+test('reverting an action pin to a floating tag fails the hardening assertion (mutation probe)', () => {
+  const text = read(WORKFLOW);
+  const mutated = text.replace(
+    `actions/checkout@${PINNED_ACTIONS['actions/checkout']}`,
+    'actions/checkout@v4',
+  );
+  assert.notEqual(mutated, text, 'the probe must mutate the workflow');
+  assert.throws(() => assertHardening(mutated), /full 40-char commit SHA/);
+});
+
+test('changing a pinned action SHA fails the hardening assertion (mutation probe)', () => {
+  const text = read(WORKFLOW);
+  const mutated = text.replace(
+    `actions/setup-node@${PINNED_ACTIONS['actions/setup-node']}`,
+    `actions/setup-node@${'a'.repeat(40)}`,
+  );
+  assert.notEqual(mutated, text, 'the probe must mutate the workflow');
+  assert.throws(() => assertHardening(mutated), /must be pinned to the committed full commit SHA/);
+});
+
+test('removing the workflow-level permissions block fails the hardening assertion (mutation probe)', () => {
+  const text = read(WORKFLOW);
+  const mutated = text.replace(/^permissions:\n  contents: read\n\n/m, '');
+  assert.notEqual(mutated, text, 'the probe must mutate the workflow');
+  assert.throws(() => assertHardening(mutated), /permissions: contents: read/);
+});
diff --git a/tests/formatting-policy.test.mjs b/tests/formatting-policy.test.mjs
new file mode 100644
index 0000000..34a8b44
--- /dev/null
+++ b/tests/formatting-policy.test.mjs
@@ -0,0 +1,249 @@
+/**
+ * Formatting/lint policy test — locks in the workspace formatting and lint
+ * policy (E00-S05-T01, CI stage 3: formatting/lint).
+ *
+ * Policy (every file tracked by git, i.e. every committed text file):
+ *   - LF line endings: no carriage returns (no CRLF, no lone CR)
+ *   - no UTF-8 byte-order mark
+ *   - no trailing whitespace on any line
+ *   - no tab characters anywhere (indentation is spaces)
+ *   - exactly one final newline: the file must end with `\n`, with no blank
+ *     line left at the end of the file
+ * JSON files additionally must:
+ *   - parse as strict JSON (no trailing commas, no comments)
+ *   - contain no duplicate object keys
+ *   - use 2-space indentation (every line's leading spaces are an even count)
+ *
+ * The scan is scoped to files tracked by git (`git ls-files`), so ignored and
+ * generated files (node_modules/, dist/, .env, probe scratch files) never
+ * enter the policy. Binary files (containing a NUL byte) are skipped.
+ *
+ * Mutation probes prove every rule is non-vacuous: each violation below is
+ * injected into a temp file and must be reported.
+ *
+ * Run: `pnpm lint` (== `node --test tests/formatting-policy.test.mjs`)
+ * (node:test — built into Node >= 18; no dependencies, lockfile untouched.)
+ */
+
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync, mkdtempSync, writeFileSync, rmSync } from 'node:fs';
+import { spawnSync } from 'node:child_process';
+import os from 'node:os';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const REPO_ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
+
+const read = (relPath) => readFileSync(path.join(REPO_ROOT, relPath), 'utf8');
+
+/** True for binary files: the policy applies to text files only. */
+const isBinary = (content) => content.includes('\0');
+
+/**
+ * Returns the list of tracked files (git ls-files, NUL-delimited) under the
+ * given repo root, or fails the suite when git is unavailable.
+ */
+function trackedFiles(root = REPO_ROOT) {
+  const result = spawnSync('git', ['-C', root, 'ls-files', '-z'], { encoding: 'utf8' });
+  assert.equal(result.status, 0, `git ls-files must succeed in ${root}`);
+  return result.stdout.split('\0').filter((p) => p.length > 0);
+}
+
+/**
+ * Collects the duplicate object keys of a JSON document. JSON.parse collapses
+ * duplicate keys (last value wins) before any reviver or post-parse walker can
+ * see them, so this scans the raw text: a string literal immediately followed
+ * by `:` is an object key, and keys are tracked per enclosing `{…}` frame, so
+ * same-named keys in different objects stay legal while a repeated key inside
+ * one object is reported.
+ */
+function collectDuplicateKeys(text, out) {
+  const frames = [];
+  let i = 0;
+  const n = text.length;
+  while (i < n) {
+    const ch = text[i];
+    if (ch === '"') {
+      let j = i + 1;
+      while (j < n && text[j] !== '"') {
+        if (text[j] === '\\') j += 1;
+        j += 1;
+      }
+      const key = text.slice(i + 1, j).replace(/\\"/g, '"').replace(/\\\\/g, '\\');
+      let k = j + 1;
+      while (k < n && (text[k] === ' ' || text[k] === '\t' || text[k] === '\n' || text[k] === '\r')) k += 1;
+      if (text[k] === ':' && frames.length > 0) {
+        const seen = frames[frames.length - 1];
+        if (seen.has(key)) out.push(`duplicate JSON key: ${key}`);
+        seen.add(key);
+      }
+      i = k;
+      continue;
+    }
+    if (ch === '{') {
+      frames.push(new Set());
+      i += 1;
+      continue;
+    }
+    if (ch === '}') {
+      frames.pop();
+      i += 1;
+      continue;
+    }
+    i += 1;
+  }
+}
+
+/**
+ * Returns the formatting/lint violations for one file relative to `root`, or
+ * [] when the file conforms. Binary files are out of policy scope.
+ */
+function violationsForFile(root, relPath) {
+  let content;
+  try {
+    content = readFileSync(path.join(root, relPath), 'utf8');
+  } catch (err) {
+    return [`${relPath}: unreadable: ${err.message}`];
+  }
+  if (isBinary(content)) return [];
+
+  const label = (message) => `${relPath}: ${message}`;
+  const out = [];
+
+  if (content.includes('\r')) out.push(label('carriage return (use LF line endings)'));
+  if (content.startsWith('\uFEFF')) out.push(label('UTF-8 byte-order mark'));
+  if (content.includes('\t')) out.push(label('tab character (indentation must be spaces)'));
+
+  const lines = content.split('\n');
+  lines.forEach((line, i) => {
+    if (/[ \t]+$/.test(line)) out.push(label(`trailing whitespace on line ${i + 1}`));
+  });
+
+  if (content.length > 0) {
+    if (lines[lines.length - 1] !== '') out.push(label('missing final newline'));
+    else if (lines[lines.length - 2] === '') out.push(label('blank line at end of file'));
+  }
+
+  if (relPath.endsWith('.json')) {
+    let parsed;
+    try {
+      parsed = JSON.parse(content);
+    } catch (err) {
+      out.push(label(`invalid JSON: ${err.message}`));
+      return out;
+    }
+    const duplicateKeys = [];
+    collectDuplicateKeys(content, duplicateKeys);
+    for (const message of duplicateKeys) out.push(label(message));
+    lines.forEach((line, i) => {
+      const indent = /^([ ]*)\S/.exec(line);
+      if (indent && indent[1].length % 2 !== 0) {
+        out.push(label(`JSON indentation must be 2 spaces per level (line ${i + 1})`));
+      }
+    });
+  }
+
+  return out;
+}
+
+/** Writes a probe file into a fresh temp dir and returns its violations. */
+function probeViolations(filename, content) {
+  const dir = mkdtempSync(path.join(os.tmpdir(), 'eppp-format-policy-'));
+  try {
+    writeFileSync(path.join(dir, filename), content);
+    return violationsForFile(dir, filename);
+  } finally {
+    rmSync(dir, { recursive: true, force: true });
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Real-tree scan
+// ---------------------------------------------------------------------------
+
+test('every tracked text file conforms to the formatting/lint policy', () => {
+  const files = trackedFiles();
+  assert.ok(
+    files.length >= 25,
+    `expected a meaningful tracked file set to scan (got ${files.length})`,
+  );
+  const violations = [];
+  for (const file of files) violations.push(...violationsForFile(REPO_ROOT, file));
+  assert.deepEqual(violations, [], `formatting/lint violations:\n${violations.join('\n')}`);
+});
+
+test('the scan covers the workspace source, docs, manifests and workflow', () => {
+  const files = trackedFiles();
+  for (const expected of [
+    'apps/server/src/index.ts',
+    'packages/config/src/env.ts',
+    'docs/development/non-container.md',
+    'package.json',
+    'pnpm-lock.yaml',
+    'pnpm-workspace.yaml',
+    'compose.yaml',
+    '.gitea/workflows/ci.yml',
+  ]) {
+    assert.ok(files.includes(expected), `tracked file set must include ${expected}`);
+  }
+});
+
+// ---------------------------------------------------------------------------
+// Mutation probes — every rule is non-vacuous
+// ---------------------------------------------------------------------------
+
+test('a trailing whitespace is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.txt', 'line with trailing space \n');
+  assert.ok(violations.some((v) => /trailing whitespace/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('a tab character is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.txt', 'line\twith tab\n');
+  assert.ok(violations.some((v) => /tab character/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('a CRLF line ending is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.txt', 'line\r\n');
+  assert.ok(violations.some((v) => /carriage return/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('a UTF-8 byte-order mark is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.txt', '\uFEFFline\n');
+  assert.ok(violations.some((v) => /byte-order mark/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('a missing final newline is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.txt', 'no final newline');
+  assert.ok(violations.some((v) => /missing final newline/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('a blank line at the end of the file is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.txt', 'line\n\n');
+  assert.ok(violations.some((v) => /blank line at end of file/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('invalid JSON is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.json', '{"a": 1,}\n');
+  assert.ok(violations.some((v) => /invalid JSON/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('a duplicate JSON key is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.json', '{"a": 1, "a": 2}\n');
+  assert.ok(violations.some((v) => /duplicate JSON key/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('odd JSON indentation is reported (mutation probe)', () => {
+  const violations = probeViolations('probe.json', '{\n  "a": 1,\n   "b": 2\n}\n');
+  assert.ok(violations.some((v) => /2 spaces per level/.test(v)), `got: ${violations.join('; ')}`);
+});
+
+test('binary files are out of policy scope (mutation probe)', () => {
+  const violations = probeViolations('probe.bin', 'a\0b');
+  assert.deepEqual(violations, []);
+});
+
+test('a conforming file yields no violations (mutation probe)', () => {
+  const violations = probeViolations('probe.json', '{\n  "a": 1\n}\n');
+  assert.deepEqual(violations, []);
+});