feat: frontend Gitea — workspaces 2 sections + gitea workspace vue

workspaces.html:
- Section 📁 Local Workspaces (existante, avec badges)
- Section 🔗 Gitea Projects (par organisation, lazy load)
- États: loading, not_linked (lien pour login OAuth), error (retry), ok

gitea_workspace.html:
- Arbre fichiers (lazy: un dossier à la fois)
- Vue fichier (lecture seule → bouton Edit)
- Éditeur avec zone de commit (message + historique dropdown)
- Section 🔒 Private Pages (placeholder pour pages FlowDeck locales)
- Bouton Delete fichier

Routing: /gitea-workspace?owner=X&repo=Y

Fallback: token admin serveur si pas de token OAuth utilisateur

app/routers/dashboard.py

@@ -393,6 +393,20 @@ async def workspace_page(request: Request):
     return template.render(**ctx)
 
 
+@router.get("/gitea-workspace", response_class=HTMLResponse)
+async def gitea_workspace_page(request: Request):
+    """Gitea workspace — browse repo files."""
+    from jinja2 import Environment, FileSystemLoader
+    env = Environment(loader=FileSystemLoader("app/templates"))
+    sidebar = _sidebar_data(request, [])
+    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
+    if not user:
+        return RedirectResponse("/auth/login?provider=local", status_code=302)
+    ctx = {**sidebar, "user": user}
+    template = env.get_template("gitea_workspace.html")
+    return template.render(**ctx)
+
+
 @router.get("/api/workspace/projects")
 async def list_workspace_projects(request: Request):
     """List all projects: built-in + Gitea + GitHub."""

app/routers/gitea.py

@@ -6,11 +6,12 @@ router = APIRouter(tags=["gitea"], prefix="/api/gitea")
 
 
 def _require_gitea(request: Request):
-    """Return a per-user GiteaClient or raise 401."""
-    from app.services.gitea_client import get_user_gitea_client
+    """Return a per-user GiteaClient or fallback to admin token."""
+    from app.services.gitea_client import get_user_gitea_client, GiteaClient
     client = get_user_gitea_client(request)
     if not client:
-        raise HTTPException(status_code=401, detail="Gitea account not linked. Login with Gitea or connect in Settings.")
+        # Fallback to server admin token
+        client = GiteaClient()
     return client