feat: static sites feature with Gitea/GitHub/GitLab support and Deno backend

Deploy static content from Git repository folders with optional server-side
API endpoints. Supports Gitea/Forgejo/Gogs, GitHub, and GitLab with provider
autodetection.

- New Sites entity with CRUD, encrypted secrets, and manual/push/tag sync triggers
- Pluggable GitProvider interface with three implementations
- Deno container mode: auto-generates router from API_{method}_{name} exports
- Static container mode: nginx serving files with optional markdown rendering
- Wizard UI with provider selector, repo picker, branch/folder tree pickers
- Deploy pipeline builds fresh image, starts container, configures NPM proxy
- Stop/Start buttons, force redeploy on manual trigger
- Periodic health checker detects crashed containers
- Proxy route existence check during auto-sync

cmd/server/main.go

@@ -32,6 +32,7 @@ import (
 	"github.com/alexei/docker-watcher/internal/proxy"
 	"github.com/alexei/docker-watcher/internal/registry"
 	"github.com/alexei/docker-watcher/internal/stale"
+	"github.com/alexei/docker-watcher/internal/staticsite"
 	"github.com/alexei/docker-watcher/internal/store"
 	"github.com/alexei/docker-watcher/internal/webhook"
 )
@@ -280,8 +281,16 @@ func main() {
 	}
 	scheduleAutobackup(settings.BackupEnabled, settings.BackupIntervalHours)
 
+	// Initialize static site manager and health checker.
+	staticSiteMgr := staticsite.NewManager(db, dockerClient, proxyProvider, eventBus, encKey)
+	staticSiteHealth := staticsite.NewHealthChecker(db, dockerClient, staticSiteMgr)
+	if err := staticSiteHealth.Start("2m"); err != nil {
+		slog.Warn("failed to start static site health checker", "error", err)
+	}
+
 	// Build API server.
 	apiServer := api.NewServer(db, dockerClient, npmClient, proxyProvider, dep, webhookHandler, eventBus, encKey)
+	apiServer.SetStaticSiteManager(staticSiteMgr)
 	apiServer.SetStaleScanner(staleScanner)
 	apiServer.SetBackupEngine(backupEngine)
 	apiServer.SetDBPath(dbPath)
@@ -341,6 +350,7 @@ func main() {
 	// Stop accepting new work.
 	cronScheduler.Stop()
 	eventBus.Unsubscribe(notifySub)
+	staticSiteHealth.Stop()
 	staleScanner.Stop()
 	poller.Stop()