Fix Axis websocket SSL cert regression with RTSP fallback

[Kane610]

Reported here home-assistant/core#169953

Summary

Fixes a regression where Axis websocket event startup on HTTPS could fail with self-signed/private-CA certificates and then repeatedly retry websocket without degrading to RTSP event stream behavior.

What changed

1. Reuse the configured device aiohttp session for websocket connects.
2. Classify websocket connect failures, including certificate verification failures.
3. Disable websocket for the current runtime on certificate verification failure (unless websocket force mode is enabled).
4. Keep websocket force mode authoritative.
5. Add targeted regression tests for websocket SSL/fallback behavior.
6. Add HA Core rollout/documentation notes.

Files

• axis/websocket.py
• axis/stream_manager.py
• tests/test_websocket.py
• tests/test_stream_manager.py
• .github/ha-core-notes-169953.md

Validation

• uv run pytest tests/test_websocket.py tests/test_stream_manager.py
• uv run ruff check axis tests
• uv run ruff format --check axis tests

Notes for Home Assistant Core

See .github/ha-core-notes-169953.md for integration-facing behavior and follow-up guidance tied to issue #169953.