Add username search and improve chat creation UX

Backend user search:

- Added users search endpoint for @username lookup.

- Implemented repository/service/router support with bounded result limits.

Web chat creation:

- Added API client for /users/search.

- Added NewChatPanel for creating private chats via @username search.

- Added group/channel creation flow from sidebar.

UX refinement:

- Hide message composer when no chat is selected.

- Show explicit placeholder: 'Выберите чат, чтобы начать переписку'.

- Added tsbuildinfo ignore rule.

app/users/repository.py

@@ -1,4 +1,4 @@
-from sqlalchemy import select
+from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.users.models import User
@@ -31,3 +31,19 @@ async def list_users_by_ids(db: AsyncSession, user_ids: list[int]) -> list[User]
         return []
     result = await db.execute(select(User).where(User.id.in_(user_ids)))
     return list(result.scalars().all())
+
+
+async def search_users_by_username(
+    db: AsyncSession,
+    *,
+    query: str,
+    limit: int = 20,
+    exclude_user_id: int | None = None,
+) -> list[User]:
+    normalized = query.lower().strip().lstrip("@")
+    stmt = select(User).where(func.lower(User.username).like(f"%{normalized}%"))
+    if exclude_user_id is not None:
+        stmt = stmt.where(User.id != exclude_user_id)
+    stmt = stmt.order_by(User.username.asc()).limit(limit)
+    result = await db.execute(stmt)
+    return list(result.scalars().all())

app/users/router.py

@@ -4,8 +4,8 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.auth.service import get_current_user
 from app.database.session import get_db
 from app.users.models import User
-from app.users.schemas import UserProfileUpdate, UserRead
-from app.users.service import get_user_by_id, get_user_by_username, update_user_profile
+from app.users.schemas import UserProfileUpdate, UserRead, UserSearchRead
+from app.users.service import get_user_by_id, get_user_by_username, search_users_by_username, update_user_profile
 
 router = APIRouter(prefix="/users", tags=["users"])
 
@@ -15,6 +15,24 @@ async def read_me(current_user: User = Depends(get_current_user)) -> UserRead:
     return current_user
 
 
+@router.get("/search", response_model=list[UserSearchRead])
+async def search_users(
+    query: str,
+    limit: int = 20,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+) -> list[UserSearchRead]:
+    if len(query.strip().lstrip("@")) < 2:
+        return []
+    users = await search_users_by_username(
+        db,
+        query=query,
+        limit=limit,
+        exclude_user_id=current_user.id,
+    )
+    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)

app/users/schemas.py

@@ -25,3 +25,11 @@ class UserRead(UserBase):
 class UserProfileUpdate(BaseModel):
     username: str | None = Field(default=None, min_length=3, max_length=50)
     avatar_url: str | None = Field(default=None, max_length=512)
+
+
+class UserSearchRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: int
+    username: str
+    avatar_url: str | None = None

app/users/service.py

@@ -16,6 +16,22 @@ async def get_user_by_username(db: AsyncSession, username: str) -> User | None:
     return await repository.get_user_by_username(db, username)
 
 
+async def search_users_by_username(
+    db: AsyncSession,
+    *,
+    query: str,
+    limit: int = 20,
+    exclude_user_id: int | None = None,
+) -> list[User]:
+    safe_limit = max(1, min(limit, 50))
+    return await repository.search_users_by_username(
+        db,
+        query=query,
+        limit=safe_limit,
+        exclude_user_id=exclude_user_id,
+    )
+
+
 async def update_user_profile(
     db: AsyncSession,
     user: User,