TUI worker status never finalizes (ghost 'running' workers after completion)

[n1arash]

Summary

TUI worker status never finalizes. After a feature completes, controller.workers[...] entries stay status="running" forever, so the WorkerScreen shows ghost "running" workers.

Evidence (dogfood campaign — Pilot-surfaced)

• A no-TUI build returned phase=done while ('e2e','running') lingered in controller.workers.
• Caught directly by the Textual Pilot driver. This is the only TUI-state defect found across the whole campaign (every gate was otherwise fully driveable with no crashes and no state-vs-display mismatches).

Why it matters

Operators see workers that appear to still be running after the feature is done — a misleading state display.

Proposed fix

Finalize every WorkerLog on phase/run completion — set a terminal status (e.g. done/failed) so no worker is left running once its phase ends.

Acceptance criteria

• On phase/run completion, every worker entry transitions to a terminal status.
• No worker remains status="running" once the controller reports phase=done.
• Regression test: drive a build to completion and assert no lingering running workers.

Source: dogfood/ITERATION_REPORT.md MINOR-8; TUI/gate findings section.