Add composer selection formatting tray

[klopez4212]

Summary

• Add a floating formatting tray above selected composer text.
• Reuse the existing formatting toolbar controls for inline selection formatting.
• Update mock E2E workspace seeding to the current buzz-* storage keys.

Validation

• cd desktop && ../bin/pnpm check
• cd desktop && ../bin/pnpm build
• cd desktop && ../bin/pnpm test
• Captured a mock snapshot with selected composer text and the tray visible.

[klopez4212]

🤖 ### Composer Format Tray
Selecting text in the composer opens the inline formatter above the selection.

[klopez4212]

🤖 ### Composer Format Tray Selecting text in the composer opens the inline formatter above the selection.

Its right above the content in the actual work..not sure why the snapshot has it in the place it does