0.6.27 - upstream sync and watchdog recovery

Synchronizes this fork with upstream 0.6.27 and its new vehicle-card tutorial. Our command fixes, native controls, climate modes, evcc compatibility and optional vehicle card were accepted upstream in PR #5.

• The watchdog now uses REST odometer/drive-state evidence to recognize movement while the MQTT push stream is stalled. Confirmed movement can use the existing bounded recovery allowance; a Standby state alone is not treated as driving.
• Includes upstream's vehicle-card tutorial and documentation updates.
• Main now follows upstream directly with one small fork-metadata commit: 1 ahead, 0 behind at publication. The old main and complete fork history are preserved at tag archive/main-before-upstream-sync-20261024; existing release tags were kept.

Existing HACS installations update normally. Other local Git clones based on the old fork main need to be deliberately realigned after fetching, rather than merging the archived main history back in.

The optional card still requires Install and manage the XPENG Vehicle dashboard card under Configure. Existing entity IDs and evcc interfaces are preserved. Minimum Home Assistant remains 2024.7. The credential renewal app is versioned independently.

Validation: 65/65 isolated regression scripts, 1,008 discovery tests (3 skipped), 30 card tests, documentation build and GitHub Tests/Docs workflows passed. Runtime code matches upstream exactly apart from the fork's issue-tracker URL. No additional physical vehicle tests are claimed.