chore(skills): promote skills/ to a first-class repo-root directory

[BorisTyshkevich]

Summary

• Moves ship and ship-phase out of .claude/skills into a new root-level skills/ directory, so it's one shared source of truth instead of being nested under a single tool's dotfolder.
• Symlinks .claude/skills, .agents/skills, and .codex/skills (new) to ../skills so Claude Code, generic agent tooling, and the Codex CLI all resolve the same files.
• Updates .gitignore for the new layout: the vendored impeccable skill's ignore rule now targets /skills/impeccable/, and the old per-item .agents/skills/* negation pattern is gone (replaced by one shared symlink instead of two per-skill ones).
• Adds a new sql-browser-dashboard skill (vendored from a local review copy): turns an already-known SQL/result-column investigation into a validated PortableBundleV2 Dashboard bundle and publishes it via the save_dashboard MCP tool, or leaves the bundle as a downloadable JSON file when that tool isn't wired up in a given deployment.
• Also folds in a small pre-existing WIP edit to skills/ship/{SKILL.md,references/unattended.md,references/per-issue-cycle.md} that was sitting uncommitted, adding a chatgpt-review-skill-based third-party review step to /ship (steps 7-8). Note: no chatgpt-review skill currently exists in this repo — this step will no-op/error until that skill is added separately.

Review of the vendored skill

Verified sql-browser-dashboard's authoring profile field-for-field against this repo's real schemas (schemas/portable-bundle-v2.schema.json, dashboard-v2.schema.json, dashboard-layout-flow-v1.schema.json, saved-query-v2.schema.json, query-spec-v1.schema.json): bundle/dashboard/layout formats, the panel type enum (bar/hbar/line/area/pie/kpi/table/logs/text), and fieldConfig fields all match exactly — no invented fields or fabricated panel types found. Its own scripts/validate_bundle.py passes cleanly against its own references/example-dashboard.json. The save_dashboard MCP write path it targets is real prior art (matching infra exists in a sibling bentoclick repo) and is correctly scoped as external/deployment-specific rather than assumed to be wired up in this repo.

Test plan

• npm run check:schemas && npm run check:examples && npm run check:arch — pass
• npm run check:types / npm test — could not run in this environment: node_modules/.bin/* symlinks are unreadable here (pre-existing environment permission issue, unrelated to this change — this PR touches no source, test, or build config, only skills/, .gitignore, and the three tool-convention symlinks)
• Verified all three symlinks (.claude/skills, .agents/skills, .codex/skills) resolve to ship, ship-phase, sql-browser-dashboard
• Verified skills/impeccable/ is still correctly gitignored under the new layout

🤖 Generated with Claude Code

https://claude.ai/code/session_01L3pqYYJrP8zAmLmrJvzcxx