fix: improve message actions across desktop and touch

[shakkernerd]

Summary

• replace persistent mobile message controls with a long-press action sheet
• preserve a keyboard and assistive-technology entry point for touch devices
• trap sheet focus, restore the opener, and support short landscape viewports
• clean up pointer listeners and copy-status timers safely
• keep desktop action toolbars above message content
• contain right-edge tooltips within the message viewport
• add regression coverage for touch and desktop interactions

Testing

• web typecheck
• message reactions E2E: 10 passed
• message editing E2E: 7 passed
• production build repeated without output changes
• local and AWS Crabbox bundles matched exactly
• desktop and mobile visual verification

[clawsweeper]

ClawSweeper status: review started.

I am starting a fresh review of this pull request: fix: improve message actions across desktop and touch This is item 1/1 in the current shard. Shard 0/1.

This placeholder means the worker is alive and reading the current context. I will edit this same comment with the actual review when the claws are done clicking.

Crustacean status: shell secured, claws on keyboard, evidence pebbles being sorted.

[shakkernerd]

Merged using rebase.

What changed after review:

• Preserved the accepted desktop toolbar and touch action-sheet behavior.
• Stabilized the keyboard-accessibility E2E coverage without changing production code.
• Kept generated web assets synchronized with the source build.

Verification:

• Refreshed onto current origin/main before pushing.
• Hetzner-through-Crabbox cbx_4f54eda4fcfc: keyboard/touch test passed 10 consecutive two-worker runs and full E2E 131/131.
• AWS Crabbox cbx_02fc6dd464ff: web typecheck, lint, formatting, 72 touched E2E tests, and full E2E 131/131 passed.
• Exact-head calibrated review clean.
• GitHub checks: all checks green.

Landed on main:

• Final landed SHA: 6ddb0eaee60c5844ed068bec223624824e6a7bb5; range b6fbb729d5638911484954d24580f6bfcb73f460...6ddb0eaee60c5844ed068bec223624824e6a7bb5.

Thanks @shakkernerd!