fix: PROTECTION MODE IS ENABLED error when protection mode is OFF

Fixes #2307

Changes:
- Update bashio from v0.17.5 → main branch (improved API error handling)
- Add robust protection mode check with Docker socket fallback
- Implement Level 1 (standard bashio) + Level 2 (socket check) fallback logic
- Update CHANGELOG.md with fix details
- Tested and verified working on Home Assistant OS with protection mode OFF

The fix addresses root cause: bashio v0.17.5 calls /addons/self endpoint
which returns 403 Forbidden. bashio's error handling incorrectly assumes
this means protection mode is ON. The fallback checks Docker socket directly
as a reliable indicator of actual protection mode state.

portainer_agent/config.yaml

@@ -41,4 +41,4 @@ schema:
 slug: portainer_agent
 udev: true
 url: https://github.com/alexbelgium/hassio-addons
-version: "alpine-sts"
+version: "alpine-sts-bashio-fix"