feat: add tip rotation system with version-update and tip widgets

[Avimarzan]

Summary

Adds a tip rotation system that surfaces useful tips from Claude Code changelogs directly in the status line. Includes:

• 2 new widgets:
  • version-update — shows Updated: vX.Y.Z → vA.B.C from the latest non-expired tip file
  • tip — shows a rotating tip from the merged pool of all non-expired tip files (💡 emoji prefix, sequential rotation)
• Core utility module (src/utils/tips.ts):
  • Sync storage for tip files, last-version tracking, and tip index (matches existing codebase patterns)
  • Semver comparison with pre-release suffix handling
  • Tip pool merging, rotation with in-memory caching (only writes to disk on actual rotation, not every render)
  • Changelog fetching from GitHub Releases API
  • Async tip generation via claude --print with <TIPS> marker extraction
  • Pipeline orchestrator: version check → changelog fetch → tip generation → file write → expiry cleanup
• Config schema extension (TipsSettingsSchema):
  • enabled, tipDir, rotateEvery, expiryDays, maxTipLength, minTips — all with sensible defaults
  • Settings version bumped 3→4 with automatic migration
• TUI config screen (TipsMenu):
  • Toggle enabled/disabled, edit numeric settings
  • Browse all tips grouped by version with age display
  • Generate tips for current Claude Code version
  • Rotate now, clear all tips
• Hook handler integration: handleHook() checks for version changes and triggers tip generation when tips.enabled is true

New files

File	Purpose
src/widgets/Tip.ts	Tip rotation widget with hideWhenEmpty toggle
src/widgets/VersionUpdate.ts	Version update notification widget
src/utils/tips.ts	Core tip utility (storage, rotation, generation, cleanup)
src/types/TipData.ts	Zod schemas for TipFile, LastVersion, TipIndex
src/tui/components/TipsMenu.tsx	TUI configuration screen
src/test-helpers/tips.ts	Shared test helpers

Modified files

File	Change
src/types/Settings.ts	Added TipsSettingsSchema, bumped version 3→4
src/utils/migrations.ts	Added v3→v4 migration
src/utils/widget-manifest.ts	Registered version-update and tip widgets
src/widgets/index.ts	Exported new widgets
src/tui/App.tsx	Added Tips screen routing
src/tui/components/MainMenu.tsx	Added Tips menu item
src/tui/components/index.ts	Exported TipsMenu
src/ccstatusline.ts	Extended hook handler for version checking

Test coverage

44 tests across 3 test files, all passing:

• src/utils/__tests__/tips.test.ts — 27 tests (storage, rotation, semver, pool, expiry, pipeline)
• src/widgets/__tests__/Tip.test.ts — 8 tests (rendering, hideWhenEmpty, preview, raw mode)
• src/widgets/__tests__/VersionUpdate.test.ts — 9 tests (rendering, empty version guard, semver ordering, expiry)

Design decisions

• Additive only — no modifications to existing widget behavior or rendering pipeline
• Follows existing patterns — sync filesystem I/O (matches skills.ts), Zod schemas, widget interface, TUI component structure
• Performance-conscious — tip pool cached in memory, disk writes only on rotation (not every render)
• Async tip generation — uses promisify(execFile) to avoid blocking the event loop in the TUI

Test plan

• Verify bun test passes (44 tip tests + existing suite)
• Add tip and version-update widgets via TUI, confirm they render
• Test TUI Tips menu: browse, generate, rotate, clear
• Test with no tip files (widgets should show placeholder or hide)
• Test expiry cleanup with old tip files

🤖 Generated with Claude Code