fix: remove unnecessary urllib3<2.0 constraint

The urllib3<2.0 constraint was added unnecessarily during troubleshooting.
urllib3 2.x works perfectly fine with qdrant-client. The import path for
urllib3.util.Url and parse_url remains the same across 1.x and 2.x versions.

Changes:
- Remove urllib3<2.0 constraint from pyproject.toml
- Upgrade to urllib3 2.5.0 (latest)
- All integration tests pass with urllib3 2.x

Verified:
- from urllib3.util import Url, parse_url works in 2.5.0
- All 6 semantic search integration tests pass
- qdrant-client 1.15.1 works correctly with urllib3 2.5.0

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

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

pyproject.toml

@@ -21,8 +21,7 @@ dependencies = [
     "pyjwt[crypto]>=2.8.0",
     "aiosqlite>=0.20.0", # Async SQLite for refresh token storage
     "authlib>=1.6.5",
-    "qdrant-client>=1.7.0", # Vector database for semantic search
-    "urllib3<2.0",
+    "qdrant-client>=1.7.0",
 ]
 classifiers = [
     "Development Status :: 4 - Beta",