feat(cli): Add 24-hour caching to version update checker

[kiloconnect]

Summary

This PR adds caching functionality to the CLI version update checker to avoid checking the npm registry on every invocation.

Changes

• Caching Implementation: Added file-based cache stored in ~/.kilocode/cli/global/version-check-cache.json
• Cache Duration: 24 hours (configurable via CACHE_DURATION_MS constant)
• Error Handling: Gracefully handles cache corruption, file system errors, and network failures
• Fallback Strategy: Falls back to cached data when npm registry is unavailable
• Test Coverage: Comprehensive test suite covering all caching scenarios

Requirements Met

✅ Performs async check at CLI startup (already existed)
✅ Uses npm registry API via package-json package (already existed)
✅ Displays helpful update message (already existed)
✅ Non-blocking async operation (already existed)
✅ Handles errors gracefully (already existed + enhanced)
✅ NEW: Rate-limiting via 24-hour cache to avoid checking on every invocation

Technical Details

The cache stores:

• lastChecked: Timestamp of last check
• latestVersion: Latest version from npm
• isOutdated: Boolean indicating if update is available

Cache validation:

• Checks if cache file exists and is valid JSON
• Validates cache structure (correct types)
• Checks if cache age is less than 24 hours
• Falls back to npm registry if cache is invalid or expired

Testing

Added comprehensive test suite (cli/src/utils/__tests__/auto-update.test.ts) covering:

• Fresh npm fetch when no cache exists
• Cache hit when cache is valid
• Cache miss when cache is expired
• Error handling for corrupted cache
• Error handling for network failures
• Fallback to cached data on errors
• File system error handling

Performance Impact

• Before: npm registry API call on every CLI invocation
• After: npm registry API call once per 24 hours
• Benefit: Reduced network requests, faster CLI startup, better offline experience

[changeset-bot]

🦋 Changeset detected

Latest commit: 05ebcac

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@kilocode/cli	Patch

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[kiloconnect]

✅ No Issues Found

3 files reviewed | Confidence: 95% | Recommendation: Merge

Review Details

Files:

• .changeset/cli-version-check-caching.md - Proper changeset format
• cli/src/utils/auto-update.ts - Caching implementation
• cli/src/utils/__tests__/auto-update.test.ts - Comprehensive test suite

Checked: Security, bugs, performance, error handling

Highlights:

• ✅ Proper error handling with silent failures for optional caching
• ✅ Cache validation checks types of all fields before use
• ✅ Graceful fallback to cached data on network errors
• ✅ Directory creation ensured before writing cache
• ✅ Comprehensive test coverage (13 test cases)
• ✅ Proper kilocode_change markers per AGENTS.md guidelines
• ✅ Changeset included with correct @kilocode/cli: patch format