feat: add local voice input and workflow refinements

[GCWing]

Summary

• add local speech input service/model management in core and desktop APIs
• wire voice input settings, composer controls, SpeechAPI, and localized UI text
• refine workflow surfaces including Work Center selection, date range dialog, timeline context metadata, search, and daily letter UI
• update project verification guidance for risk-based checks

Tests

• cargo fmt --check --package sparo-core --package sparo-desktop
• cargo check -p sparo-desktop
• pnpm run type-check:web
• pnpm --dir src/web-ui exec vitest run src/flow_chat/services/ContextBudgetService.test.ts src/flow_chat/store/FlowChatStore.metadata.test.ts