refactor(voice): compact call controls on mobile

[JulioMCruz]

Summary

• replace oversized voice actions with accessible circular call/connecting/hang-up controls and adjacent status text
• make phone layouts a bounded Conversation/Settings workspace with a sticky call surface, independently scrolling history, reachable composer, and safe-area padding
• preserve Normal/Private, mute, duration, desktop behavior, and external/managed policy

Validation

• focused tests: 16 passed
• full suite: 362 passed
• typecheck and changed-file lint passed
• production build passed all 51 routes with non-secret CI placeholders
• diff/secret checks clean