feat: account management panel — /accounts + /api/users/me

- Page /accounts: profil utilisateur éditable, comptes connectés, workspace members
- API GET/PUT /api/users/me: lecture/écriture profil local (full_name, email)
- Users list from local DB, auth via Gitea OAuth2
- Imports SessionManager clean dans api.py

app/routers/dashboard.py

@@ -82,6 +82,20 @@ async def view_page_root(request: Request, page_id: int):
     return template.render(**ctx)
 
 
+@router.get("/accounts", response_class=HTMLResponse)
+async def accounts_page(request: Request):
+    """Account management panel."""
+    from jinja2 import Environment, FileSystemLoader
+    env = Environment(loader=FileSystemLoader("app/templates"))
+    sidebar = _sidebar_data(request, [])
+    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
+    with get_conn() as conn:
+        users = conn.execute("SELECT * FROM users ORDER BY created_at DESC").fetchall()
+    ctx = {**sidebar, "user": user, "users": [dict(u) for u in users]}
+    template = env.get_template("accounts.html")
+    return template.render(**ctx)
+
+
 @router.get("/", response_class=HTMLResponse)
 async def dashboard(
     request: Request,