feat(app): add session project menu and polish header

[iamdavidhill]

Issue for this PR

No linked issue; requested session-header UI updates.

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

• Turn the local/worktree icon into a project menu: select the project on Home, open its session folder locally, or edit the project.
• Limit the menu to 320px and show wrapping tooltips above truncated names and paths. Add the supplied diagonal arrow and hover fade to the path row.
• Keep 2px gaps between header controls, reduce title padding, and stop the title jumping when editing. Left-align the content-sized options menu with full-width rows and divider.
• Refresh existing SVG sprites after hot reload so newly added icons render.

How did you verify your code works?

• Seven Chromium regressions passed against a production build: local/worktree menus, LTR/RTL, truncation/tooltips, Home selection, editing alignment, options sizing, and stale icon sprites.
• App, E2E, and UI typechecks passed; the pre-push hook also passed all 33 workspace typecheck tasks.
• Production cold-session benchmark, three serial runs per version: median first-correct rendering 216.3 → 233.5 ms; stable rendering 230.6 → 247.3 ms. These are small diagnostic samples, not a performance guarantee.
• Native Finder launch was not exercised by the browser tests; the action uses the existing desktop openPath integration and is disabled for web/remote sessions.

Screenshots / recordings

Browser fixture (native folder opening is disabled):

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR