feat: app health endpoint succeeds (E00-S02-T03)

apps/server/Dockerfile

@@ -2,13 +2,14 @@
 
 # @personal-blog/server — EPPP public server application image.
 #
-# [E00-S02-T01] baseline: builds the workspace server package with the pinned
-# toolchain (Node 24.19.0 + pnpm 11.23.0, frozen lockfile) and runs the compiled
-# entrypoint. The server is still a bootstrap placeholder (its module loads and
-# exits cleanly); the Fastify 5 application shell that turns it into a serving
-# process lands in a later story, and the health gate (T02), health endpoint
-# (T03), volume persistence (T04), non-root/read-only hardening and multi-arch
-# targets are later E00-S02 tasks — all out of scope here.
+# [E00-S02-T01/T02/T03] baseline: builds the workspace server package with the
+# pinned toolchain (Node 24.19.0 + pnpm 11.23.0, frozen lockfile) and runs the
+# compiled entrypoint. Since T03 the entrypoint is a minimal Node `node:http`
+# server answering `GET /health` with `{"status":"ok"}` (HTTP 200) on port
+# 3000, so the app container stays up and the health endpoint succeeds. The
+# Fastify 5 application shell (and the real HTTP API) lands in a later story;
+# volume persistence (T04), non-root/read-only hardening (T05) and multi-arch
+# targets remain later E00-S02 tasks — all out of scope here.
 #
 # Image base: node:24.19.0-bookworm-slim (glibc Debian) per Technology-Stack
 # §5.4 — argon2 is a native dependency and musl/Alpine causes native-module