feat(skills): TITAN-inspired enhancements for classification, TDD, and planning

[dean0x]

Summary

• Classification rules: Add trivial-edit escape hatch — explicit single-site edits (e.g., "rename foo to bar in utils.ts") stay QUICK instead of loading GUIDED skills unnecessarily
• TDD skill: Add cycle verification checklist, 4 rationalization table rows, red flags table (mid-work detection), test-first vs code-first example, and when-stuck guide (+58 lines)
• plan:orch: Add Socratic Phase 0.5 requirements discovery with skip criteria, process steps, and escape hatch; add GUIDED step 0 for lightweight discovery
• plan.md: Harmonize Gate 0 with Socratic questioning style — skip discovery when specific, one question per message, present approaches with tradeoffs

Inspired by competitor TITAN's best prompt engineering techniques (rationalization tables, red flags, one-question-at-a-time discovery, options-with-tradeoffs), adapted to DevFlow's architecture. No new plugins, skills, or agents — content-only changes to 4 existing files.

Test plan

• npm run build succeeds (73 skill copies distributed across 17 plugins)
• npm test passes (1059 tests, 46 test files)
• Only 4 planned files modified — no scope creep
• Classification rules still contain QUICK, GUIDED, ORCHESTRATED, all 8 intents
• TDD section order matches spec: Iron Law → Cycle → Verification → Rationalization → Red Flags → Example → When Stuck → Process → Exceptions → Ambient
• plan:orch and plan.md Gate 0 harmonize (same Socratic pattern, same escape hatch)
• Architecture diagram and Clarification Gates table updated to "Requirements Discovery"