feat: persistent storage for Deno static sites

- Add storage_enabled and storage_limit_mb columns to static_sites.
- Create/attach Docker volumes (tinyforge-site-{name}-data) for Deno
  sites with storage enabled, mounted at /app/data.
- Grant --allow-write=/app/data in Deno container CMD.
- Add storage usage API endpoint (GET /api/sites/{id}/storage).
- Show storage section in site detail page with usage bar.
- Add storage toggle and limit field to new site wizard.
- Use ConfirmDialog for secret deletion instead of inline delete.

web/src/lib/types.ts

@@ -358,10 +358,18 @@ export interface StaticSite {
 	last_sync_at: string;
 	last_commit_sha: string;
 	error: string;
+	storage_enabled: boolean;
+	storage_limit_mb: number;
 	created_at: string;
 	updated_at: string;
 }
 
+export interface StaticSiteStorageUsage {
+	enabled: boolean;
+	used_bytes: number;
+	limit_mb: number;
+}
+
 export type StaticSiteStatus = 'idle' | 'syncing' | 'deployed' | 'failed' | 'stopped';
 
 export type GitProvider = '' | 'gitea' | 'github' | 'gitlab';