feat(gitops): config-as-code via .tinyforge.yml for repo-backed workloads

A dockerfile or static workload can opt in to reading its deploy config from a
.tinyforge.yml in its own repo. Tinyforge fetches the file, shows field-level
drift vs the live config, and an admin applies it with an explicit Sync. The
repo becomes the source of truth for the declared fields. Manual-sync only;
no auto-apply on deploy, no multi-workload reconcile, no create/delete in v1.

Scope is deliberately source-aware and source_config-resident: dockerfile
declares port/healthcheck/deploy_strategy, static declares deploy_strategy.
The file never carries repo coords or secrets (those stay in the encrypted
DB), which keeps credentials out of the repo.

Backend:
- internal/gitops: Spec/ParseSpec (KnownFields rejects unknown keys), a
  source-aware ApplyPlan/BuildPlan, MergeAndValidate (omitted-field-preserving
  deep merge + validate-the-merged-result-then-commit — never a partial
  config), declared-only Drift with normalization, and Fetch with
  ok/no_file/fetch_failed/invalid statuses and token-redacted messages.
- staticsite: DownloadFile added to GitProvider + Gitea/GitHub/GitLab impls,
  reusing each provider's SSRF-safe client; 64 KiB cap; ErrFileNotFound.
- store: 4 additive gitops_* columns + setters (disjoint from UpdateWorkload
  so the edit-form save and a sync never clobber each other).
- api: GET /workloads/{id}/gitops (status + raw + live drift + managed_fields),
  PUT /gitops (admin, enable/path, traversal-safe), POST /gitops/sync (admin,
  per-workload locked read->merge->validate->write, audited to event_log).

Frontend:
- GitOpsPanel.svelte: status pill, a purpose-built field-level drift view,
  .tinyforge.yml preview, enable ToggleSwitch, Sync via ConfirmDialog; all five
  statuses handled, admin affordances gated on the real viewer role.
- GitOps-managed badge (list + detail hero) and a read-only edit-form banner.
- api.ts fetchers + types; i18n apps.detail.gitops.* (en + ru parity).

Built phase-by-phase with an adversarial plan review (caught 5 design flaws
pre-implementation) and an independent review per phase (go / security / ts /
final) — all APPROVE, 0 CRITICAL/HIGH. docs/gitops.md documents the schema and
what's intentionally out of v1. Plan: plans/gitops/.

internal/api/router.go

@@ -52,6 +52,10 @@ type Server struct {
 	oidcProvider  *auth.OIDCProvider
 	staleScanner  *stale.Scanner
 
+	// gitopsSync serializes the GitOps sync (read→merge→write) per workload so
+	// two concurrent syncs can't race on source_config (review S5).
+	gitopsSync keyedMutex
+
 	dnsProviderMu        sync.RWMutex
 	dnsProvider          dns.Provider
 	onDNSProviderChanged DNSProviderChangedFunc
@@ -342,6 +346,13 @@ func (s *Server) Router() chi.Router {
 				r.Get("/deploys", s.listWorkloadDeploys)
 				r.With(auth.AdminOnly).Post("/rollback", s.rollbackWorkload)
 
+				// GitOps config-as-code (dockerfile/static). The status read
+				// (incl. live drift) is open to any authenticated user; enable/
+				// disable and sync mutate config, so they are admin-gated.
+				r.Get("/gitops", s.getWorkloadGitOps)
+				r.With(auth.AdminOnly).Put("/gitops", s.setWorkloadGitOps)
+				r.With(auth.AdminOnly).Post("/gitops/sync", s.syncWorkloadGitOps)
+
 				// Volume snapshots (admin-only). Capture/list a workload's
 				// host-bind data volumes; {sid}-scoped download/delete live
 				// in the global admin group alongside backups.