feat: workspaces system — create, select, rename, delete workspaces

- DB: pages.workspace_id column linking pages to workspaces table
- /workspaces: list, create, rename, delete workspaces page
- API: GET/POST/PUT/DELETE /api/workspaces + POST select
- Session: flowdeck_workspace cookie for active workspace tracking
- Sidebar: Workspace section shows active workspace name + page tree
- Local workspace APIs filter by active workspace_id
- Home redirects non-Gitea users to /workspaces

app/routers/dashboard.py

@@ -547,3 +547,118 @@ async def delete_local_workspace_item(request: Request, item_id: int):
         conn.execute("DELETE FROM pages WHERE id=? OR parent_id=?", (item_id, item_id))
         conn.commit()
     return {"status": "ok"}
+
+
+# ═══════════ Workspaces CRUD ═══════════
+
+WORKSPACE_COOKIE = "flowdeck_workspace"
+
+
+def _get_active_workspace(request: Request) -> dict | None:
+    """Get the active workspace ID from the cookie, or first workspace, or None."""
+    ws_id = request.cookies.get(WORKSPACE_COOKIE)
+    if ws_id:
+        try:
+            with get_conn() as conn:
+                ws = conn.execute("SELECT * FROM workspaces WHERE id=?", (int(ws_id),)).fetchone()
+                if ws:
+                    return dict(ws)
+        except (ValueError, Exception):
+            pass
+    # Fallback: first workspace
+    with get_conn() as conn:
+        ws = conn.execute("SELECT * FROM workspaces ORDER BY id LIMIT 1").fetchone()
+        if ws:
+            return dict(ws)
+    return None
+
+
+@router.get("/workspaces", response_class=HTMLResponse)
+async def workspaces_page(request: Request):
+    """Workspaces list page."""
+    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("workspaces.html")
+    return template.render(**ctx)
+
+
+@router.get("/api/workspaces")
+async def list_workspaces(request: Request):
+    """List all workspaces for the current user."""
+    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
+    uid = user["id"] if user and user.get("id") else 1
+    with get_conn() as conn:
+        rows = conn.execute(
+            "SELECT w.*, (SELECT COUNT(*) FROM pages WHERE workspace_id=w.id) as page_count "
+            "FROM workspaces w WHERE w.owner_id=? ORDER BY w.created_at DESC",
+            (uid,),
+        ).fetchall()
+    workspaces = []
+    for r in rows:
+        d = dict(r)
+        workspaces.append(d)
+    active = _get_active_workspace(request)
+    return {"workspaces": workspaces, "active_id": active["id"] if active else None}
+
+
+@router.post("/api/workspaces")
+async def create_workspace(request: Request):
+    """Create a new workspace."""
+    import json
+    body = await request.json()
+    name = body.get("name", "New Workspace").strip()
+    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
+    uid = user["id"] if user and user.get("id") else 1
+    with get_conn() as conn:
+        cursor = conn.execute(
+            "INSERT INTO workspaces (name, owner_id) VALUES (?, ?)",
+            (name, uid),
+        )
+        conn.commit()
+        ws_id = cursor.lastrowid
+        # Add owner as member
+        conn.execute(
+            "INSERT INTO workspace_members (workspace_id, user_id, role) VALUES (?, ?, 'owner')",
+            (ws_id, uid),
+        )
+        conn.commit()
+    return {"id": ws_id, "name": name}
+
+
+@router.put("/api/workspaces/{ws_id:int}")
+async def rename_workspace(request: Request, ws_id: int):
+    """Rename a workspace."""
+    import json
+    body = await request.json()
+    name = body.get("name", "").strip()
+    if not name:
+        return {"error": "Name required"}
+    with get_conn() as conn:
+        conn.execute("UPDATE workspaces SET name=? WHERE id=?", (name, ws_id))
+        conn.commit()
+    return {"status": "ok"}
+
+
+@router.delete("/api/workspaces/{ws_id:int}")
+async def delete_workspace(request: Request, ws_id: int):
+    """Delete a workspace and all its pages."""
+    with get_conn() as conn:
+        conn.execute("DELETE FROM pages WHERE workspace_id=?", (ws_id,))
+        conn.execute("DELETE FROM workspace_members WHERE workspace_id=?", (ws_id,))
+        conn.execute("DELETE FROM workspaces WHERE id=?", (ws_id,))
+        conn.commit()
+    return {"status": "ok"}
+
+
+@router.post("/api/workspaces/{ws_id:int}/select")
+async def select_workspace(request: Request, ws_id: int):
+    """Set the active workspace via cookie."""
+    from fastapi.responses import JSONResponse
+    response = JSONResponse({"status": "ok", "workspace_id": ws_id})
+    response.set_cookie(WORKSPACE_COOKIE, str(ws_id), max_age=86400 * 30, httponly=True, path="/")
+    return response