feat(app): mention file via context menu in file tree

[alexyaroshuk]

What does this PR do?

1. adds right-click context menu to the file tree:

feat-add-file-tree-context-menu.mp4

2. adds right-click context menu to the session tabs:

feat-add-session-tabs-context-menu.mp4

3. Adds following actions:

File tree:

• Open (file only)
• Mention in prompt

4. new keys in i18n for 'mention', 'close others'

Session tabs:

• Close
• Close others - closes other tabs
• Mention in prompt

How did you verify your code works?

Manual testing, e2e tests, and unit tests.

Files changed

Files	What Changed
packages/app/src/components/file-tree.tsx	Added context menu with static import; added context menu to folders; fixed spacing/flashing bugs; full-width hover area
packages/app/src/components/session-sortable-tab.tsx	Added context menu via static import
packages/app/src/components/session.tsx	Added mentionFile(), closeOtherTabs(), mentionTab() functions
packages/app/src/components/session-side-panel.tsx	Wired context menu callbacks to components
packages/app/src/components/file-tree.test.ts	Added context menu mock for server-side tests
packages/app/src/i18n/*.ts	Added translations for 'mention', 'closeTab', 'closeOthers'

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

No duplicate PRs found

[alexyaroshuk]

reworked to align with refactored session/session side panel, & merged the other pr in, please check @adamdotdevin , thanks.

[alexyaroshuk]

@adamdotdevin i solved the test failure - could you this a look?

[cpkt9762]

@adamdotdevin i solved the test failure - could you this a look?
Dude, I agree with you, I want to make the same menu too.

[alexyaroshuk]

update:

1. Static import in file tree to avoid hydration flash on folder expand.
2. test file (packages/app/src/components/file-tree.test.ts): ContextMenu is mocked in tests for SSR compatibility.