feat: postgresql migration and removal of sqlite in pytest (#546)

* feat: remove support of sqlite, 100% postgres

* fix: more migration and make datetime timezone aware in postgres

* fix: change how database is get, and use contextvar to have difference instance between different loops

* test: properly use client fixture that handle lifetime/database connection

* fix: add missing client fixture parameters to test functions

This commit fixes NameError issues where test functions were trying to use
the 'client' fixture but didn't have it as a parameter. The changes include:

1. Added 'client' parameter to test functions in:
   - test_transcripts_audio_download.py (6 functions including fixture)
   - test_transcripts_speaker.py (3 functions)
   - test_transcripts_upload.py (1 function)
   - test_transcripts_rtc_ws.py (2 functions + appserver fixture)

2. Resolved naming conflicts in test_transcripts_rtc_ws.py where both HTTP
   client and StreamClient were using variable name 'client'. StreamClient
   instances are now named 'stream_client' to avoid conflicts.

3. Added missing 'from reflector.app import app' import in rtc_ws tests.

Background: Previously implemented contextvars solution with get_database()
function resolves asyncio event loop conflicts in Celery tasks. The global
client fixture was also created to replace manual AsyncClient instances,
ensuring proper FastAPI application lifecycle management and database
connections during tests.

All tests now pass except for 2 pre-existing RTC WebSocket test failures
related to asyncpg connection issues unrelated to these fixes.

* fix: ensure task are correctly closed

* fix: make separate event loop for the live server

* fix: make default settings pointing at postgres

* build: remove pytest-docker deps out of dev, just tests group

server/reflector/views/transcripts.py

@@ -3,12 +3,12 @@ from typing import Annotated, Literal, Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Query
 from fastapi_pagination import Page
-from fastapi_pagination.ext.databases import paginate
+from fastapi_pagination.ext.databases import apaginate
 from jose import jwt
 from pydantic import BaseModel, Field, field_serializer
 
 import reflector.auth as auth
-from reflector.db import database
+from reflector.db import get_database
 from reflector.db.meetings import meetings_controller
 from reflector.db.rooms import rooms_controller
 from reflector.db.search import (
@@ -48,7 +48,7 @@ DOWNLOAD_EXPIRE_MINUTES = 60
 
 def create_access_token(data: dict, expires_delta: timedelta):
     to_encode = data.copy()
-    expire = datetime.utcnow() + expires_delta
+    expire = datetime.now(timezone.utc) + expires_delta
     to_encode.update({"exp": expire})
     encoded_jwt = jwt.encode(to_encode, settings.SECRET_KEY, algorithm=ALGORITHM)
     return encoded_jwt
@@ -141,8 +141,8 @@ async def transcripts_list(
 
     user_id = user["sub"] if user else None
 
-    return await paginate(
-        database,
+    return await apaginate(
+        get_database(),
         await transcripts_controller.get_all(
             user_id=user_id,
             source_kind=SourceKind(source_kind) if source_kind else None,