feat: add trace case corpus and camera evidence

[Gracker]

Summary

• add a versioned Trace case corpus with 6 real cases, 12 deterministic constructed cases, generated overlays, private import/promotion guards, and coverage contracts
• cover 231 runtime Skills and 21 Strategies with 252 regression expectations, including semantic, graceful-empty, unavailable, and definition-only outcomes
• include the prerequisite evidence-first camera workflow and exported SQL compatibility fixes that were already present in the local branch
• verify the public Skill projection through the paired repository immutable snapshot contract instead of comparing against local compiler overlays

Cross-repository evidence

• decision: required
• fingerprint: d75550a1695d266911072216600e24c33275a6b2568b2255ed5c45320402d324
• paired Perfetto-Skills commit: 093b5541449767e2a0aa8625c0700b06c7f028d6
• paired branch: feat/smartperfetto-trace-corpus-sync

Verification

• npm run trace:regression — 18 cases, 12 constructed builds, 252 expectations
• npm run verify:pr — passed, including 6-trace scene regression
• npm run test:governance — 11/11
• npm run shellcheck — passed
• PERFETTO_SKILLS_DIR=/Users/chris/Code/SmartPerfetto/Perfetto-Skills npm run verify:public-skills — 231 Skills, 65 strategy sources, 32 pipeline docs, catalog valid
• paired Perfetto-Skills full gate — 165 tests, 643/643 queries, full fixture tier

This draft intentionally includes all predecessor camera commits and all trace-corpus commits from the local branch.

Paired PR

• chore: sync SmartPerfetto trace corpus Perfetto-Skills#1