feat: Integrated SQLite database and project history into B2B Marketing Assistant

- market_db_manager.py: Made DB_PATH configurable via environment variable.

- Dockerfile.b2b: Included market_db_manager.py in the B2B container image.

- docker-compose.yml: Configured separate DB paths and volumes for Market Intel and B2B Assistant.

- B2B Server: Added API routes for project management (list, load, save, delete).

- B2B UI: Implemented auto-save and a 'Project History' modal for loading past runs.

Dockerfile.b2b

@@ -45,6 +45,7 @@ COPY --from=frontend-builder /app/dist ./dist
 
 # Copy the main Python orchestrator script from the project root
 COPY b2b_marketing_orchestrator.py .
+COPY market_db_manager.py .
 # Copy Gemini API Key file if it exists in root
 COPY gemini_api_key.txt .