feat: add search APIs and telegram-like chats sidebar flow

- implement chat query filtering and message search endpoints

- add db indexes for search fields

- activate chats search input in web

- replace inline create panel with floating TG-style action menu

app/messages/repository.py

@@ -1,6 +1,7 @@
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from app.chats.models import ChatMember
 from app.messages.models import Message, MessageIdempotencyKey, MessageReceipt, MessageType
 
 
@@ -76,6 +77,31 @@ async def list_chat_messages(
     return list(result.scalars().all())
 
 
+async def search_messages(
+    db: AsyncSession,
+    *,
+    user_id: int,
+    query: str,
+    chat_id: int | None = None,
+    limit: int = 50,
+) -> list[Message]:
+    stmt = (
+        select(Message)
+        .join(ChatMember, ChatMember.chat_id == Message.chat_id)
+        .where(
+            ChatMember.user_id == user_id,
+            Message.text.is_not(None),
+            Message.text.ilike(f"%{query.strip()}%"),
+        )
+        .order_by(Message.id.desc())
+        .limit(limit)
+    )
+    if chat_id is not None:
+        stmt = stmt.where(Message.chat_id == chat_id)
+    result = await db.execute(stmt)
+    return list(result.scalars().all())
+
+
 async def delete_message(db: AsyncSession, message: Message) -> None:
     await db.delete(message)
 

app/messages/router.py

@@ -4,7 +4,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.auth.service import get_current_user
 from app.database.session import get_db
 from app.messages.schemas import MessageCreateRequest, MessageRead, MessageStatusUpdateRequest, MessageUpdateRequest
-from app.messages.service import create_chat_message, delete_message, get_messages, update_message
+from app.messages.service import create_chat_message, delete_message, get_messages, search_messages, update_message
 from app.realtime.schemas import MessageStatusPayload
 from app.realtime.service import realtime_gateway
 from app.users.models import User
@@ -27,6 +27,17 @@ async def create_message(
     return message
 
 
+@router.get("/search", response_model=list[MessageRead])
+async def search_messages_endpoint(
+    query: str,
+    chat_id: int | None = None,
+    limit: int = 50,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+) -> list[MessageRead]:
+    return await search_messages(db, user_id=current_user.id, query=query, chat_id=chat_id, limit=limit)
+
+
 @router.get("/{chat_id}", response_model=list[MessageRead])
 async def list_messages(
     chat_id: int,

app/messages/service.py

@@ -76,6 +76,29 @@ async def get_messages(
     return await repository.list_chat_messages(db, chat_id, limit=safe_limit, before_id=before_id)
 
 
+async def search_messages(
+    db: AsyncSession,
+    *,
+    user_id: int,
+    query: str,
+    chat_id: int | None = None,
+    limit: int = 50,
+) -> list[Message]:
+    normalized = query.strip()
+    if len(normalized) < 2:
+        return []
+    safe_limit = max(1, min(limit, 100))
+    if chat_id is not None:
+        await ensure_chat_membership(db, chat_id=chat_id, user_id=user_id)
+    return await repository.search_messages(
+        db,
+        user_id=user_id,
+        query=normalized,
+        chat_id=chat_id,
+        limit=safe_limit,
+    )
+
+
 async def update_message(
     db: AsyncSession,
     *,