Fix meetings bot row state refresh - #331

Summary

• refresh visible meeting rows through the per-event bot lookup before using the legacy full bot list
• keep previous bot row state if the per-event lookup fails instead of overwriting from a lossy fallback
• encode calendar event IDs in the Tauri bot-list query and cover the new lookup merge rules

Validation

• pnpm exec vitest run src/desktop-alt/lib/meetings-model.test.ts src/lib/meetingsCache.test.ts
• pnpm run lint
• pnpm run build
• pnpm test
• pnpm run test:e2e:desktop-alt
• pnpm run sidecar:install
• cargo test --locked query_value_encoding_preserves_safe_event_ids_and_escapes_reserved_chars