fix(server): serialize shared device operations

[yltx]

Summary

• add a token-owned, non-blocking lease for the shared emulator
• reserve the device before task worker startup and release it only after the worker exits
• serialize all direct UI-driving routes, including acquisition OCR and expedition auto-check
• keep task stop, status, health, and cached context reads available while the device is busy
• prevent system startup or context teardown from racing active device work

Busy operations return HTTP 409 instead of waiting. expedition_auto_check no longer performs expedition/reward navigation concurrently with a combat task.

Verification

• uv run --frozen pytest testing/server -q (40 passed)
• uv run --frozen pytest -n auto --cov=autowsgr --cov-report=xml --cov-report=term-missing --junitxml=junit.xml (581 passed)
• uv run --frozen pre-commit run ruff-check --all-filesn- uv run --frozen pre-commit run ruff-format --all-filesn- uv run --frozen pre-commit run codespell --all-files`n
  The lease implementation itself has 100% local line coverage. Full pre-commit --all-files remains subject to the repository's known Windows symlink checkout artifact; Ubuntu CI is authoritative for the complete hook suite.

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[yltx]

Coverage verification

Codecov did not create a codecov/patch check for this PR, even after the same head SHA was uploaded twice successfully by the Pytest workflow. Both uploads reported Upload queued for processing complete; GitHub has received no Codecov check or status for �d8af909700fb52efaa84d9f7d4c2c60f069cc20.

This is an absent external result, not a failed coverage result. I verified the same patch locally against origin/main using the CI-generated coverage.xml:

` ext
uvx diff-cover coverage.xml --compare-branch origin/main --fail-under=53.17

Total: 96 patch lines
Missing: 2 lines
Coverage: 97%
`

Per-file patch coverage:

• �utowsgr/server/device_lease.py: 100%
• �utowsgr/server/routes/game.py: 100%
• �utowsgr/server/routes/ops.py: 90.9%
• �utowsgr/server/routes/system.py: 100%
• �utowsgr/server/routes/task.py: 93.3%
• �utowsgr/server/task_manager.py: 100%

GitHub Lint and Pytest are both successful; the complete suite reports 581 passed. No Codecov threshold or repository configuration was weakened.