Standardize local worker and cache commands

[MaxEriksson2000]

Summary

• expose the ARQ worker as the project script uv run worker
• preserve additional CLI arguments through a small worker entry point
• update Taskfile and setup documentation to use the stable command
• add frontend cache cleanup and dev:clean scripts

Why

The documented worker command depended on an internal module path, and clearing stale frontend build caches required remembering several directories. Stable project-level commands make local setup and recovery less error-prone.

Developer impact

Local development can start the worker through task worker or uv run worker, and can clear generated frontend caches with bun run clean:cache or restart cleanly with bun run dev:clean.

Validation

• Ruff passed
• worker entry-point import smoke test passed
• commit hooks including Pyright passed
• pre-push schema drift check passed

[github-actions]

🧹 Dead-code & unused-dependency report

Advisory — never gates the PR. Whole-repo scan, so some findings may be false positives (dynamic dispatch, framework hooks, runtime-resolved imports). Triage before removing.

✅ No dead code or unused dependencies detected.

[github-actions]

📊 Patch coverage

Share of this PR's new/changed lines exercised by tests. Report-only — never gates the PR.

No changed lines with coverage data in this PR.