feat: add environment endpoint for weather, forecast, and sun data

Add GET /tools/environment endpoint that fetches weather, forecast, sun times,
and air quality data from user's volatile Qdrant collection.

- Add qdrant-client dependency
- Create QdrantReadClient wrapper for read-only queries
- Add environment schemas and service in tools domain
- Parse weather, forecast, sun times, and air quality from Qdrant payloads
- Support user-specific collections via preferred_username from OIDC
- Add comprehensive service tests (13 tests)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

requirements.txt

@@ -32,3 +32,6 @@ cryptography>=44.0.1  # CVE-2024-12797
 sqlalchemy[asyncio]~=2.0.0
 asyncpg>=0.30.0
 alembic~=1.13.0
+
+# Vector Database
+qdrant-client>=1.9.0