fix(deploy,db,handler): close fresh-clone postgres init failure + 4 ride-along audit findings (U-3 master)

GitHub #10 reopened: operator mikeakasully cloned v2.0.50 fresh and ran the
canonical quickstart (docker compose -f deploy/docker-compose.yml up -d --build);
postgres reported unhealthy indefinitely, dependent containers never started.

Root cause: deploy/docker-compose.yml mounted a hand-curated subset of
migrations/*.up.sql + seed.sql into postgres /docker-entrypoint-initdb.d/.
Postgres applied them at initdb time. Once seed.sql referenced columns added
by migrations *after* the mounted cutoff (e.g., policy_rules.severity from
migration 000013), initdb crashed mid-seed and the container loop wedged.
Two sources of truth (compose mount list vs in-tree migration ladder)
diverged the moment a seed-touching migration shipped, and the only thing
that fixed it was hand-editing the compose file every release.

Fix: remove the dual source. Postgres boots empty; the server applies
migrations + seed at startup via RunMigrations + RunSeed. Helm has used
this pattern since day one (postgres-init emptyDir); compose now matches.

Bundled with four ride-along audit findings whose fixes share the same
schema/db code surface, so operators take the schema-change pain only once:

  cat-u-seed_initdb_schema_drift           [P1, primary] — initdb-mount fix
  cat-o-retry_interval_unit_mismatch       [P1] — column rename minutes→seconds
  cat-o-notification_created_at_dead_field [P2] — add column + populate
  cat-o-health_check_column_orphans        [P1] — drop unwired columns
  cat-u-no_version_endpoint                [P2] — add /api/v1/version

Single migration (000017_db_coupling_cleanup) bundles the three schema
changes under a DO \$\$ guard so re-application is safe; reduces
operator-visible 'schema-change releases' from four to one.

Backend
- internal/repository/postgres/db.go: add RunSeed (baseline) + RunDemoSeed
  (gated by CERTCTL_DEMO_SEED). Both idempotent (ON CONFLICT DO NOTHING in
  every shipped INSERT) so repeated boots are safe; missing-file is no-op
  so custom packaging that strips seeds still boots cleanly.
- cmd/server/main.go: invoke RunSeed (always) + RunDemoSeed (when flag set)
  immediately after RunMigrations.
- internal/repository/postgres/notification.go: NotificationRepository.Create
  now sets created_at (with time.Now() fallback when caller leaves it zero);
  scanNotification reads it back; List + ListRetryEligible SELECT extended.
- internal/repository/postgres/renewal_policy.go: column references updated
  to retry_interval_seconds across SELECT/INSERT/UPDATE sites.
- internal/api/handler/version.go: new VersionHandler exposes
  {version, commit, modified, build_time, go_version} from
  runtime/debug.ReadBuildInfo() with ldflags-supplied Version override.
- internal/api/router/router.go: register GET /api/v1/version through the
  no-auth chain (CORS + ContentType) alongside /health, /ready,
  /api/v1/auth/info.
- cmd/server/main.go: add /api/v1/version to no-auth dispatch + audit
  ExcludePaths so rollout polling doesn't dominate the audit trail.
- internal/config/config.go: add DatabaseConfig.DemoSeed +
  CERTCTL_DEMO_SEED env var.

Migration
- migrations/000017_db_coupling_cleanup.up.sql + .down.sql:
    (1) renewal_policies.retry_interval_minutes → retry_interval_seconds
        (DO \$\$ guard, idempotent re-application)
    (2) notification_events ADD COLUMN created_at TIMESTAMPTZ
        NOT NULL DEFAULT NOW()
    (3) network_scan_targets DROP orphan health_check_enabled +
        health_check_interval_seconds
- migrations/seed.sql: column reference updated to retry_interval_seconds.
- migrations/seed_demo.sql: same column rename + applied at runtime now via
  RunDemoSeed (no longer initdb-mounted).

Compose
- deploy/docker-compose.yml: drop ALL initdb mounts (10 migration files +
  seed.sql); add start_period: 30s to postgres + certctl-server healthchecks
  to absorb the runtime migration + seed application window on first boot.
- deploy/docker-compose.test.yml: same drop (+ ghost seed_test.sql mount
  removed; that file never existed); same healthcheck start_period.
- deploy/docker-compose.demo.yml: replace seed_demo.sql initdb mount with
  CERTCTL_DEMO_SEED=true env var on certctl-server.

Tests
- internal/api/handler/version_handler_test.go: TestVersion_ReturnsBuildInfo,
  TestVersion_RejectsNonGet, TestVersion_LdflagsOverride.
- internal/repository/postgres/seed_test.go: TestRunSeed_AppliesIdempotently,
  TestRunSeed_MissingFileIsNoOp, TestRunDemoSeed_AppliesIdempotently,
  TestMigration000017_RetryIntervalRename,
  TestMigration000017_NotificationCreatedAt,
  TestMigration000017_HealthCheckOrphansDropped (testcontainers, -short skips).
- internal/repository/postgres/notification_test.go:
  TestNotificationRepository_CreatedAt_IsPersisted +
  TestNotificationRepository_CreatedAt_DefaultsToNow.

CI guardrail
- .github/workflows/ci.yml: new 'Forbidden migration mount in compose initdb
  (U-3)' step grep-fails the build if any migrations/*.sql or seed*.sql
  re-appears in /docker-entrypoint-initdb.d in any compose file. Catches
  future drift before a fresh-clone operator hits it.

Spec / Docs
- api/openapi.yaml: add /api/v1/version operation under Health tag.
- docs/architecture.md: replace the 'initdb may run the same SQL' paragraph
  with a post-U-3 single-source-of-truth explanation.
- CHANGELOG.md: full unreleased-section entry covering all 5 closures,
  breaking changes, and the new env var.

Audit doc
- coverage-gap-audit-2026-04-24-v5/unified-audit.md: add new P1 #14
  cat-u-seed_initdb_schema_drift; flip the 4 ride-along findings to
  ✅ RESOLVED with closure prose pointing at this commit.

Verification: build/vet/test -short -race all clean across all touched
packages locally; govulncheck reports 0 vulnerabilities affecting our
code; OpenAPI YAML parses; CI U-3 grep guardrail clears against the
post-fix tree.

deploy/docker-compose.yml

@@ -53,6 +53,29 @@ services:
       - certctl-network
 
   # PostgreSQL database
+  #
+  # U-3 (P1, cat-u-seed_initdb_schema_drift, GitHub #10):
+  # Pre-U-3 this stack mounted a hand-curated subset of `migrations/*.up.sql`
+  # plus `seed.sql` into `/docker-entrypoint-initdb.d/`, and postgres
+  # initdb-applied them on first boot. The mount list rotted every time a
+  # new migration shipped that the seed depended on (000013 added
+  # policy_rules.severity, 000017 renames retry_interval_minutes, etc.) —
+  # initdb crashed, the container reported `unhealthy` indefinitely, and
+  # `docker compose -f deploy/docker-compose.yml up -d --build` from a
+  # fresh clone of v2.0.50 hit it on the first try.
+  #
+  # Post-U-3 the schema is built EXCLUSIVELY by the server at startup via
+  # internal/repository/postgres.RunMigrations + RunSeed. Single source of
+  # truth, no list to keep in sync. Postgres comes up empty; the server
+  # waits for it healthy, then applies the full migration ladder + seed in
+  # one shot. Helm + the dev examples were already runtime-only (Path B)
+  # and worked through the same window.
+  #
+  # `start_period: 30s` gives postgres room to bootstrap on slow runners
+  # (CI macOS, low-spec laptops) before the healthcheck failure counter
+  # starts ticking. Pre-U-3 a slow first-init combined with the
+  # `unhealthy` flap to cascade into certctl-server's `service_healthy`
+  # depends_on, blocking the whole stack.
   postgres:
     image: postgres:16-alpine
     container_name: certctl-postgres
@@ -64,17 +87,6 @@ services:
       - "5432:5432"
     volumes:
       - postgres_data:/var/lib/postgresql/data
-      - ../migrations/000001_initial_schema.up.sql:/docker-entrypoint-initdb.d/001_schema.sql
-      - ../migrations/000002_agent_metadata.up.sql:/docker-entrypoint-initdb.d/002_agent_metadata.sql
-      - ../migrations/000003_certificate_profiles.up.sql:/docker-entrypoint-initdb.d/003_certificate_profiles.sql
-      - ../migrations/000004_agent_groups.up.sql:/docker-entrypoint-initdb.d/004_agent_groups.sql
-      - ../migrations/000005_revocation.up.sql:/docker-entrypoint-initdb.d/005_revocation.sql
-      - ../migrations/000006_discovery.up.sql:/docker-entrypoint-initdb.d/006_discovery.sql
-      - ../migrations/000007_network_discovery.up.sql:/docker-entrypoint-initdb.d/007_network_discovery.sql
-      - ../migrations/000008_verification.up.sql:/docker-entrypoint-initdb.d/008_verification.sql
-      - ../migrations/000009_issuer_config.up.sql:/docker-entrypoint-initdb.d/009_issuer_config.sql
-      - ../migrations/000010_target_config.up.sql:/docker-entrypoint-initdb.d/010_target_config.sql
-      - ../migrations/seed.sql:/docker-entrypoint-initdb.d/020_seed.sql
     networks:
       - certctl-network
     healthcheck:
@@ -82,6 +94,7 @@ services:
       interval: 5s
       timeout: 5s
       retries: 5
+      start_period: 30s
     restart: unless-stopped
 
   # Certctl Server (API + scheduler)
@@ -127,6 +140,11 @@ services:
       interval: 10s
       timeout: 5s
       retries: 5
+      # U-3: server boot now does RunMigrations + RunSeed before listening on
+      # 8443. On a fresh clone the full migration ladder + seed application
+      # can take ~10s on a small VM; start_period prevents the first few
+      # healthcheck attempts from counting as failures while that work runs.
+      start_period: 30s
     restart: unless-stopped
     logging:
       driver: "json-file"