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+# Technology stack
+
+Researched 2026-08-26. Three support classes (§5.1): **A** = fixed upstream EOL date; **B** = documented support policy, no fixed multi-year date; **C** = rolling, exact-pinned + tested + upgraded deliberately.
+
+## Runtime stack (§5.2)
+
+| Layer | Version | Class |
+|---|---|---|
+| Node.js | 24.19.0 LTS (Krypton) | A |
+| TypeScript | 6.0.3 | C |
+| Fastify | 5.12.1 | B |
+| PostgreSQL | 18.6 | A |
+| `pg` | 8.22.0 | C |
+| Kysely | 0.29.4 | C |
+| React / React DOM | 19.2.8 | C |
+| `@sinclair/typebox` | 0.34.52 | project-designated LTS |
+| Ajv | 8.20.0 | C |
+| Pino | 10.3.1 | B |
+| `argon2` | 0.45.1 | C |
+| `@fastify/cookie` / `helmet` / `rate-limit` / `static` / `csrf-protection` / `swagger` | 11.1.2 / 13.1.1 / 11.2.0 / 10.1.3 / 8.0.1 / 9.8.1 | Fastify lifecycle |
+| `@fastify/multipart` | 10.1.1 | C/ecosystem (CI gate before enabling) |
+
+## v1.1 verification note (§5.2.1)
+
+An independent re-check on 2026-08-27 found: **TypeScript verified correct** (7.0 GA'd 2026-07-08 without a stable programmatic API before 7.1; 6.0 is the bridge). **PostgreSQL "18.6" could not be confirmed** — postgresql.org shows 18.3 (2026-02-26) with quarterly minors, placing late August at 18.4/18.5. Sprint 0 re-runs the provenance table (§74) and commits the re-verified tuple. A "verified" pin is trusted for one sprint, not the life of the document.
+
+## Build/admin/test toolchain (§5.3)
+
+Vite 8.2.2 · `@vitejs/plugin-react` 6.1.0 · pnpm 11.23.0 · Vitest 4.1.10 · Playwright 1.62.1 · Docker Engine 29.7.2 (CI ref) · Docker Compose 5.5.0 (CI ref) · Caddy 2.11.4 (optional).
+
+## Golden compatibility tuple (§7)
+
+Every release candidate must pass the full integration suite on: Node 24.19.0, TypeScript 6.0.3, Fastify 5.12.1, PostgreSQL 18.6, pg 8.22.0, Kysely 0.29.4, React/React DOM 19.2.8, TypeBox 0.34.52, Ajv 8.20.0, Pino 10.3.1. Certified container platforms: `linux/amd64`, `linux/arm64`. Playwright runs Chromium, Firefox, WebKit.
+
+## Container image pins (§5.4)
+
+```text
+node:24.19.0-bookworm-slim      # application (glibc → argon2 native deps)
+postgres:18.6-bookworm
+caddy:2.11.4-alpine             # optional edge profile
+```
+
+Release automation records immutable image digests in an SBOM/release manifest.
+
+## Version discipline (§8)
+
+Direct platform dependencies are exact-pinned in release branches; the lockfile is committed; no caret ranges for core runtime/build deps. `packageManager: pnpm@11.23.0`, `engines.node: 24.x`.
+
+Update lanes: **Security emergency** (immediate, focused + full CI) · **Patch** (weekly batch) · **Minor** (monthly review) · **Major** (explicit programme item: ADR + migration/compatibility).
+
+## LTS strategy (§6)
+
+- **Node 24** EOL 2028-04-30; evaluate Node 26 only after it is LTS + compatibility CI passes; major change requires ADR.
+- **PostgreSQL 18** supported to 2030-11-14; always run current minor; major upgrade is a separate operator procedure.
+- **Fastify 5** — no fixed EOL claimed; upgrade to v6 gated on: stable v6, all plugins compatible, full suite green, extension contracts stable/migrated, ADR.
+- **React** — exact-pinned 19.2.8, no RSC in v1, kept out of persisted content formats.
+- **TypeScript** — 6.0.3 baseline, formal review after TS 7.1 stable.
+- **Kysely** — pre-1.0, contained inside the PostgreSQL adapter; domain/extension packages never import it.