Resolve #25 -- Add simple task/queue actions to the inspector

[codingjoe]

No description provided.

[Copilot]

Pull request overview

Adds interactive “mutating” queue/task actions to the Textual-based inspector (confirm/retype modals + keyboard bindings), backed by new backend APIs and Redis implementations, with accompanying tests and README updates.

Changes:

• Add confirmation modal screens (ConfirmScreen, PurgeScreen) and dialog styling for inspector actions.
• Add inspector keybindings/actions to requeue failed tasks, dequeue tasks, and purge queues (with confirmation flows).
• Extend backend API with dequeue() / purge() and implement them (plus extra Redis cleanup in requeue()), with expanded test coverage and docs.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
threadmill/inspector/screens.py	Adds modal confirmation screens for destructive/confirmable inspector actions.
threadmill/inspector/inspector.scss	Adds dialog styling and global screen alignment (needs scoping adjustment).
threadmill/inspector/app.py	Adds keybindings and action handlers for refresh/requeue/dequeue/purge in the inspector.
threadmill/backends/redis.py	Adds Redis implementations for dequeue/purge and improves requeue cleanup.
threadmill/backends/base.py	Extends backend interface with dequeue/purge APIs and expands requeue docstring.
tests/test_inspector.py	Adds extensive inspector action and modal interaction tests.
tests/backends/test_redis.py	Adds Redis backend tests for requeue cleanup, dequeue, and purge behavior.
tests/backends/test_base.py	Adds base backend NotImplementedError tests for new APIs.
README.md	Documents inspector queue actions and shortcuts (currently mismatched for dequeue).