Polish and improve the UI

[habedi]

• Improved the organization of the test files, so related files are inside the same directories.
• Added support for building and publishing a Docker image to the GHCR.
• Added a unified theme for the UI.
• Fixed a few bugs.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 30.69307% with 560 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/ui/TodoList.tsx	0.77%	128 Missing ⚠️
src/agent/core/permissionsManager.ts	0.00%	125 Missing and 1 partial ⚠️
src/ui/ExitSummary.tsx	0.00%	69 Missing and 1 partial ⚠️
src/agent/core/state.ts	44.44%	60 Missing ⚠️
src/ui/HelpMenu.tsx	0.00%	44 Missing ⚠️
src/ui/App.tsx	0.00%	26 Missing ⚠️
src/ui/HistoryItemDisplay.tsx	69.44%	22 Missing ⚠️
src/agent/llm/textFilters.ts	66.66%	19 Missing ⚠️
src/agent/errors/stderrSuppression.ts	70.73%	4 Missing and 8 partials ⚠️
src/ui/CheckpointConfirmation.tsx	0.00%	11 Missing ⚠️
... and 9 more

📢 Thoughts on this report? Let us know!