Curate and split smoke test ownership - #2472

Fixes #2470

Summary

• repair and promote stale DTO, diagnostics, cleanup, and coverage-plan contracts
• merge duplicate documentation, blueprint-permission, and runtime-ability coverage into maintained behavioral tests
• split the default smoke aggregate into fast, integration, serial browser, and exhaustive release lanes
• replace overlapping workflow command lists with convention-based owned manifests

Evidence

• final GitHub fast contracts: 5m10 (previous npm run check: ~9m58)
• final GitHub integration: 6m16, including Docker-backed mysqli coverage
• final GitHub browser: 7m15 for all 22 serial Chromium consumers
• final PR wall time: 7m15 with owned lanes running concurrently (previous aggregate workflow: ~11m)
• local npm run check: 2m22
• npm run build
• focused repaired contract tests
• actionlint on changed workflows
• git diff --check

AI Assistance

GPT-5.6-sol via OpenCode audited stale coverage, implemented the lane split and test consolidation, and ran the verification commands above. Chris reviewed and directed the work.