feat(questions): implement questions app NestJS backend

Complete backend implementation for the AI-powered research assistant app:

Database Schema (Drizzle ORM):
- collections: Organize questions into folders with colors and icons
- questions: User questions with status, priority, tags, and research depth
- research_results: Results from mana-search service with summaries and key points
- sources: Extracted content from web search results
- answers: AI-generated answers with ratings and citations

NestJS Modules:
- QuestionModule: CRUD operations with filtering, pagination, and status management
- CollectionModule: Collection management with reordering and question counts
- ResearchModule: Integration with mana-search microservice for web search
- AnswerModule: Answer management with ratings and acceptance tracking
- SourceModule: Source content retrieval and management
- HealthModule: Health checks for database and search service

Features:
- Full JWT authentication via @manacore/shared-nestjs-auth
- Research depths: quick (5 sources), standard (15), deep (30)
- Automatic content extraction and summarization
- Follow-up question generation

Also updated:
- Root package.json: Added questions:* development scripts
- setup-databases.sh: Added questions database setup

https://claude.ai/code/session_01Rk3YVJCU3nM8uvVPghRz6r

scripts/setup-databases.sh

@@ -78,6 +78,7 @@ ALL_DATABASES=(
     "zitare_bot"
     "todo_bot"
     "nutriphi_bot"
+    "questions"
 )
 
 # Check if specific service requested
@@ -175,9 +176,13 @@ setup_service() {
             create_db_if_not_exists "nutriphi_bot"
             push_schema "@manacore/telegram-nutriphi-bot" "nutriphi-bot"
             ;;
+        questions)
+            create_db_if_not_exists "questions"
+            push_schema "@questions/backend" "questions"
+            ;;
         *)
             echo -e "${RED}Unknown service: $service${NC}"
-            echo "Available services: auth, chat, zitare, contacts, calendar, clock, todo, manadeck, mail, moodlit, finance, voxel-lava, figgos, planta, nutriphi, presi, storage, projectdoc, zitare_bot, todo_bot, nutriphi_bot"
+            echo "Available services: auth, chat, zitare, contacts, calendar, clock, todo, manadeck, mail, moodlit, finance, voxel-lava, figgos, planta, nutriphi, presi, storage, projectdoc, zitare_bot, todo_bot, nutriphi_bot, questions"
             exit 1
             ;;
     esac
@@ -201,7 +206,7 @@ echo -e "\n${GREEN}Step 2: Pushing schemas${NC}"
 echo "--------------------------------------"
 
 # Push schemas for all known services
-for service in auth chat zitare contacts calendar clock todo manadeck picture mail moodlit finance voxel-lava figgos planta nutriphi presi storage; do
+for service in auth chat zitare contacts calendar clock todo manadeck picture mail moodlit finance voxel-lava figgos planta nutriphi presi storage questions; do
     setup_service "$service" 2>/dev/null || true
 done