fix(web): polish realtime voice switch

[bobleer]

Summary

• Simplify the realtime voice mode switch into a borderless ghost action so the floating panel no longer shows nested rounded borders.
• Use a phone handset icon for realtime voice entry and active-call identity while keeping microphone icons for ASR and mute controls.
• Add a regression assertion for the realtime voice phone icon.
• Stabilize two settings Hook inputs introduced by merged PR refactor(ui): harden settings and interaction workflows #2760, clearing deterministic exhaustive-deps errors that blocked Frontend Build on the current base branch.

Type and Areas

Type: UI/UX, regression fix, CI unblock

Areas: web UI

Motivation / Impact

The previous switch duplicated the floating panel border and used the same microphone metaphor as ASR dictation. The updated control has a clearer visual hierarchy and distinguishes a realtime call from microphone input without changing behavior or copy.

The first CI run also exposed two lint errors already present in the latest 1.0.0-explore base. The follow-up keeps the latest projection request and settings draft registration in refs while preserving the existing structural rerun triggers, preventing request or registration churn.

Verification

• pnpm --dir src/web-ui run test:run src/app/components/NavPanel/unifiedSessionCreation.test.ts (9 tests passed)
• pnpm --dir src/web-ui run test:run src/infrastructure/config/components/ReasoningConfigPanel.test.tsx src/infrastructure/config/settingsDraftRegistry.test.ts (12 tests passed)
• pnpm run lint:web (0 errors; 7 pre-existing Fast Refresh warnings)
• pnpm run motion:audit (completed with no new findings; one pre-existing inventory item remains in PortForwardDialog.scss)
• pnpm run check:web (appearance, theme, typography, and type checks passed)
• Manual local Web preview: the idle switch has a transparent background and 0px border; hover and press feedback remain visible.

Reviewer Notes

The product change is presentation-only shared Web UI. Remote workspace, remote control, Peer Device Mode, and Detached Dispatch were not exercised separately because command, transport, persistence, and runtime behavior are unchanged. No user-facing strings or locale resources changed.

The settings Hook adjustment is isolated to preserving existing rerun semantics while satisfying the repository lint gate.

Checklist

• This PR is focused and does not include secrets, temporary prompts, generated scratch files, or unrelated artifacts.
• Relevant verification is recorded above, or skipped checks are explained.
• User-facing strings, docs, and locales are updated where applicable.