feat(chat): add random public_id and fix users blocked route

- add chats.public_id random identifier with migration 0011
- expose public_id in chat API payloads
- use chat public_id in message search UI label
- fix users router order so /users/blocked no longer conflicts with /users/{user_id}

app/users/router.py

@@ -41,14 +41,6 @@ async def search_users(
     return users
 
 
-@router.get("/{user_id}", response_model=UserRead)
-async def read_user(user_id: int, db: AsyncSession = Depends(get_db), _current_user: User = Depends(get_current_user)) -> UserRead:
-    user = await get_user_by_id(db, user_id)
-    if not user:
-        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
-    return user
-
-
 @router.put("/profile", response_model=UserRead)
 async def update_profile(
     payload: UserProfileUpdate,
@@ -102,3 +94,11 @@ async def unblock_user_endpoint(
     if user_id == current_user.id:
         return
     await unblock_user(db, user_id=current_user.id, blocked_user_id=user_id)
+
+
+@router.get("/{user_id}", response_model=UserRead)
+async def read_user(user_id: int, db: AsyncSession = Depends(get_db), _current_user: User = Depends(get_current_user)) -> UserRead:
+    user = await get_user_by_id(db, user_id)
+    if not user:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
+    return user