Lookup resolver: name → UUID caching

[mateicanavra]

TL;DR

Implement a lookup resolver that converts human-readable names (state, labels, projects, milestones) to Linear UUIDs, with caching to minimize API calls.

Deliverables

• scripts/linear-sync/lookups.ts module
• State name → UUID resolver (e.g., planned → acc37e31-...)
• Label name → UUID resolver (e.g., Improvement → d8655b06-...)
• Project slug → UUID resolver
• Milestone slug → UUID resolver
• Issue identifier → UUID resolver (for parent references)
• In-memory cache populated once per sync run

Acceptance Criteria

• Single API call per entity type (states, labels, projects) at sync start
• Cache persists for duration of sync run
• Graceful handling of unknown values (log warning, skip field)
• State mapping handles local names: planned→Backlog, in_progress→In Progress, done→Done
• Works with team-scoped and workspace-scoped labels

Testing / Verification

# Verify lookups resolve correctly
bun run scripts/linear-sync/lookups.ts --test

# Expected: Prints resolved UUIDs for known states/labels

Dependencies / Notes

• Depends on: @linear/sdk npm package
• Depends on: LINEAR_API_KEY environment variable
• Blocks: Sync engine (needs UUIDs to create/update issues)
• API calls: ~5 calls per sync run (states, labels, projects, milestones, team)