Add agent status feature tip

[brennanb2025]

Summary

• Adds a concrete in-app feature tip for live agent statuses in the sidebar.
• Uses the reviewed changelog GIF and links to the matching 1.3.41 release notes.

Test plan

• pnpm exec vitest run --config config/vitest.config.ts src/shared/feature-tips.test.ts src/renderer/src/components/feature-tips/feature-tip-modal-state.test.ts src/renderer/src/components/feature-tips/feature-tip-startup-gate.test.ts src/renderer/src/components/feature-tips/feature-tip-primary-action.test.ts
• pnpm run typecheck:web
• pnpm exec oxlint src/shared/feature-tips.ts src/shared/feature-tips.test.ts src/renderer/src/components/feature-tips/FeatureTipsModal.tsx src/renderer/src/components/feature-tips/feature-tip-modal-state.test.ts src/renderer/src/components/feature-tips/feature-tip-startup-gate.test.ts src/renderer/src/components/feature-tips/feature-tip-primary-action.ts src/renderer/src/components/feature-tips/feature-tip-primary-action.test.ts

Generated after feature-tip candidate review.