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.

internal/api/handler/version.go

@@ -0,0 +1,158 @@
+package handler
+
+import (
+	"net/http"
+	"runtime"
+	"runtime/debug"
+)
+
+// VersionHandler exposes the running server's build identity at
+// /api/v1/version. U-3 ride-along (cat-u-no_version_endpoint, P2): pre-U-3
+// there was no in-band way for an operator (or an automated rollout system)
+// to ask "what version of certctl is this binary?" — they had to either read
+// the container image tag externally or trust whatever the README said. The
+// gap matters for the same operability story U-3 closes: when fresh-clone
+// quickstarts fail, the very first question is "what code did I actually
+// build", and the only honest answer needs to come from the binary itself.
+//
+// VersionInfo is populated from three sources, in priority order:
+//
+//  1. The Version field — typically supplied at build time via
+//     `-ldflags='-X github.com/shankar0123/certctl/internal/api/handler.Version=v2.0.50'`.
+//     Production releases set this from the git tag (see release.yml).
+//
+//  2. runtime/debug.ReadBuildInfo() — populated by Go 1.18+ for any binary
+//     built from a module. Provides the VCS commit SHA, dirty flag, and
+//     build timestamp. We read these fields directly so a `go build` from a
+//     working tree (no -ldflags incantation) still produces a useful
+//     /api/v1/version payload — the failure mode pre-U-3 was that everything
+//     looked like "dev" everywhere, which made "is the bug fixed in this
+//     binary" unanswerable.
+//
+//  3. Static fallbacks ("dev" / "unknown") — only reached when neither
+//     ldflags nor build-info are populated, which in practice means
+//     `go run` from a non-VCS-tracked workspace.
+//
+// The handler runs through the no-auth bypass dispatch in cmd/server/main.go
+// so probes and rollout systems can query it without presenting Bearer
+// credentials, mirroring how /health and /ready are reachable. Audit logging
+// excludes /api/v1/version for the same reason — the path is hot under
+// rollout polling and would otherwise dominate the audit trail.
+type VersionHandler struct{}
+
+// Version is overridden at build time via:
+//
+//	-ldflags='-X github.com/shankar0123/certctl/internal/api/handler.Version=<tag>'
+//
+// release.yml does this for the server container and CLI/agent binaries.
+// The empty default (rather than "dev") lets the Handler fall back to the
+// runtime/debug VCS revision when ldflags wasn't supplied — preferable to
+// returning a literal "dev" that masks the actual git SHA the binary was
+// built from.
+var Version = ""
+
+// NewVersionHandler returns a value (not a pointer) to match the
+// HealthHandler convention — the handler holds no mutable state and is
+// safe to copy.
+func NewVersionHandler() VersionHandler {
+	return VersionHandler{}
+}
+
+// VersionInfo is the JSON shape returned by GET /api/v1/version.
+//
+// Field ordering and tag names are part of the contract — operator tooling
+// (k8s rollout checks, CI smoke tests, /api/v1/version Prometheus blackbox
+// probes) parses this payload and must continue to work across releases.
+// Don't rename a field without an OpenAPI bump and a deprecation cycle.
+type VersionInfo struct {
+	// Version is the human-readable release identifier (e.g. "v2.0.50").
+	// Falls back to the VCS revision when ldflags wasn't set, and to "dev"
+	// when the build wasn't VCS-tracked at all.
+	Version string `json:"version"`
+
+	// Commit is the git SHA of HEAD at build time, sourced from
+	// runtime/debug.BuildInfo.Settings["vcs.revision"]. Empty string when
+	// the binary was built outside a VCS-tracked workspace (rare —
+	// `go build` from a tarball does this).
+	Commit string `json:"commit"`
+
+	// Modified reports whether the build had uncommitted changes
+	// (debug.BuildInfo.Settings["vcs.modified"]). True for developer
+	// builds, false for release builds out of CI.
+	Modified bool `json:"modified"`
+
+	// BuildTime is the RFC 3339 timestamp captured at build time
+	// (debug.BuildInfo.Settings["vcs.time"]). Empty when not VCS-tracked.
+	BuildTime string `json:"build_time"`
+
+	// GoVersion is the Go toolchain version that compiled the binary
+	// (runtime.Version, e.g. "go1.25.9"). Useful when triaging stdlib
+	// behavior differences ("the deploy that broke was on 1.24, this one
+	// is on 1.25").
+	GoVersion string `json:"go_version"`
+}
+
+// readBuildInfo extracts the VCS settings from debug.BuildInfo and pairs
+// them with the ldflags-supplied Version. Split out from ServeHTTP so the
+// handler can be unit-tested by injecting synthetic BuildInfo (see
+// version_handler_test.go) without depending on the test binary's actual
+// debug info.
+//
+// debug.ReadBuildInfo returns ok=false when the binary was built without
+// module info — extremely rare for a Go 1.18+ build, but we guard it so
+// the handler degrades to "dev / unknown / runtime.Version()" instead of
+// nil-deref panicking.
+func readBuildInfo() VersionInfo {
+	info := VersionInfo{
+		Version:   Version,
+		GoVersion: runtime.Version(),
+	}
+
+	bi, ok := debug.ReadBuildInfo()
+	if !ok {
+		// Pre-Go 1.18 binary or a stripped build with no buildinfo segment.
+		// Both are pathological in 2026 but worth the two-line guard.
+		if info.Version == "" {
+			info.Version = "dev"
+		}
+		return info
+	}
+
+	for _, s := range bi.Settings {
+		switch s.Key {
+		case "vcs.revision":
+			info.Commit = s.Value
+		case "vcs.modified":
+			// debug.BuildInfo encodes this as the literal string "true" or
+			// "false"; comparing to "true" is the canonical pattern (mirrors
+			// how the standard library's own version sub-command parses it).
+			info.Modified = s.Value == "true"
+		case "vcs.time":
+			info.BuildTime = s.Value
+		}
+	}
+
+	// Fallback ladder for Version: ldflags > VCS commit > "dev". The git
+	// SHA is more useful than "dev" because it's at least groundable — an
+	// operator can `git show <sha>` to see what code is actually running.
+	if info.Version == "" {
+		if info.Commit != "" {
+			info.Version = info.Commit
+		} else {
+			info.Version = "dev"
+		}
+	}
+
+	return info
+}
+
+// ServeHTTP implements http.Handler. Returns the VersionInfo payload as
+// JSON with a 200 status. GET-only — any other method returns 405, matching
+// the HealthHandler convention.
+func (h VersionHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+	JSON(w, http.StatusOK, readBuildInfo())
+}

internal/api/handler/version_handler_test.go

@@ -0,0 +1,108 @@
+package handler
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// TestVersion_ReturnsBuildInfo is the regression for the U-3 ride-along
+// cat-u-no_version_endpoint (P2). Three behaviors must hold for the
+// endpoint to be useful in operator tooling:
+//
+//  1. GET /api/v1/version returns 200 with a JSON body that decodes into
+//     the documented VersionInfo shape — the wire contract that rollout
+//     systems and Prometheus blackbox probes parse.
+//  2. The Go runtime version always populates (runtime.Version() can never
+//     return empty), so consumers can always answer "which Go did this
+//     binary compile with" even when ldflags / VCS info are missing.
+//  3. The Version field is never empty — the fallback ladder
+//     (ldflags > VCS commit > "dev") guarantees a non-empty string so
+//     consumers don't have to special-case absent values.
+//
+// We don't pin the exact Version value because it depends on whether the
+// test binary was built with -ldflags or under `go test`, both of which
+// the handler must tolerate. The "no empty string" check is the
+// behavioral contract.
+func TestVersion_ReturnsBuildInfo(t *testing.T) {
+	h := NewVersionHandler()
+
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/version", nil)
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", rec.Code)
+	}
+
+	contentType := rec.Header().Get("Content-Type")
+	if !strings.HasPrefix(contentType, "application/json") {
+		t.Errorf("Content-Type = %q, want application/json prefix (operator tooling parses JSON)", contentType)
+	}
+
+	var got VersionInfo
+	if err := json.NewDecoder(rec.Body).Decode(&got); err != nil {
+		t.Fatalf("response body did not decode into VersionInfo: %v\nbody: %s", err, rec.Body.String())
+	}
+
+	// Version must never be empty — the fallback ladder in readBuildInfo
+	// guarantees this. An empty Version would force every downstream
+	// consumer (k8s rollouts, Prometheus blackbox, the support tooling)
+	// to special-case the missing value, which defeats the point of
+	// /api/v1/version existing.
+	if got.Version == "" {
+		t.Error("Version is empty — the fallback ladder (ldflags > VCS commit > 'dev') must guarantee a non-empty value")
+	}
+
+	// GoVersion must equal runtime.Version() — the handler reads it
+	// directly and cannot be subverted by ldflags or BuildInfo. This is
+	// the one field that should always be ground-truth.
+	if got.GoVersion != runtime.Version() {
+		t.Errorf("GoVersion = %q, want %q (must come straight from runtime.Version())",
+			got.GoVersion, runtime.Version())
+	}
+}
+
+// TestVersion_RejectsNonGet pins the GET-only contract. /api/v1/version
+// is read-only build identity; POST/PUT/DELETE etc. are nonsensical and
+// should return 405 like the HealthHandler does. Operator tooling that
+// fat-fingers the verb gets a clear error rather than a confusing 200
+// from the wrong code path.
+func TestVersion_RejectsNonGet(t *testing.T) {
+	h := NewVersionHandler()
+
+	for _, method := range []string{
+		http.MethodPost, http.MethodPut, http.MethodDelete, http.MethodPatch,
+	} {
+		req := httptest.NewRequest(method, "/api/v1/version", nil)
+		rec := httptest.NewRecorder()
+		h.ServeHTTP(rec, req)
+		if rec.Code != http.StatusMethodNotAllowed {
+			t.Errorf("%s /api/v1/version → status %d, want 405", method, rec.Code)
+		}
+	}
+}
+
+// TestVersion_LdflagsOverride locks in the priority order: when the
+// build-time Version variable is non-empty (e.g. "v2.0.50" injected by
+// release.yml), readBuildInfo MUST surface that value verbatim and not
+// silently substitute the VCS commit. The release-pipeline contract
+// depends on this — a release tagged v2.0.50 should report "v2.0.50",
+// not the underlying SHA.
+//
+// We achieve test isolation by save/restore on the package-level Version
+// variable; t.Cleanup ensures parallel/subsequent tests see the original.
+func TestVersion_LdflagsOverride(t *testing.T) {
+	original := Version
+	t.Cleanup(func() { Version = original })
+
+	Version = "v2.0.50-test"
+	got := readBuildInfo()
+	if got.Version != "v2.0.50-test" {
+		t.Errorf("Version = %q, want %q (ldflags-supplied Version must take priority over VCS fallback)",
+			got.Version, "v2.0.50-test")
+	}
+}