Add post-run automation callbacks

[malhotra5]

Summary

Implements post-run automation callbacks for APP-2489 / #208 using the callback-chain design.

• Adds durable automation_run_callbacks records with persisted callback lifecycle state.
• Adds automation-level callbacks config with exactly-one-of validation for entrypoint vs inline_python.
• Defaults automations with callbacks to keep_alive=True when keep_alive is omitted, so normal sandbox cleanup can be left to runtime TTL/reaper.
• Materializes preset inline_python callbacks into generated tarballs under callbacks/<name>.py and normalizes them to callback entrypoints.
• Schedules callbacks when runs reach COMPLETED or FAILED via either SDK completion callback or watchdog verification.
• Starts one in-sandbox Python wrapper command that runs matching callbacks sequentially in the existing workdir, captures per-callback results, and POSTs a final completion payload back to the automation service.
• Adds POST /runs/{run_id}/callbacks/complete for the wrapper completion payload and GET /runs/{run_id}/callbacks for inspecting callback records.
• Keeps explicit cleanup blocked until callbacks have been dispatched; if keep_alive=False is explicitly used, callback completion can clean up after terminal callback records.

Testing

• uv run pre-commit run --files openhands/automation/models.py openhands/automation/schemas.py openhands/automation/preset_router.py openhands/automation/router.py openhands/automation/watchdog.py openhands/automation/app.py openhands/automation/backends/base.py openhands/automation/backends/cloud.py openhands/automation/backends/local.py openhands/automation/callbacks.py migrations/versions/010_post_run_callbacks.py tests/test_callbacks.py tests/test_schemas.py tests/test_preset_router.py --show-diff-on-failure
• uv run pytest tests/test_callbacks.py tests/test_schemas.py tests/test_preset_router.py::TestGenerateTarball -q

Note: tests/test_watchdog.py could not be run in this environment because the Docker daemon is unavailable and the test fixture starts a Postgres testcontainer before executing tests.

Closes #208
Linear: APP-2489

This PR description was updated by an AI agent (OpenHands) on behalf of the user.

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