feat(skills): OutLayer-style public skill family — router, task-shaped skills, /skills serving

[elliotBraem]

What

Restructures the agent-facing skill surface around the OutLayer skills model (https://skills.outlayer.ai): a routing entry point that points at one self-contained skill per task, with worked flows, grounded error tables, and URL-addressable skill files.

Changes

Serving (every-plugin)

• packages/every-plugin/src/build/ui/factory.ts copies node_modules/{everything-dev,every-plugin,better-near-auth}/skills into every core-UI build's dist/skills/<package>/ — reachable at /skills/<package>/<skill>/SKILL.md in dev (rsbuild output.copy) and production (host static proxy already passes .md). Children resolve the same copies from the published npm tarballs since they install all three packages. _artifacts is excluded via globOptions.ignore; copy option typing widened to carry it.

Router (ui)

• ui/public/skill.md is now an entry-point router: verb-keyed task → skill table (each row links its URL and its intent id), "load ONE skill" rule, shared facts table (origins, API base, MCP, auth header, runtime config), composability pairings, and rules to work by (*.gen.*, build train, Effect handler convention, semantic Tailwind). Regression-pinned strings (/api/mcp, x-api-key, /settings/api-keys) preserved.
• llms.txt lists the family; the /skill page renders a family grid (skill.family-* testids).

Content

• New everything-dev#talk-to-the-app: MCP/REST/oRPC-RPC surfaces with real route paths, API-key auth, discovery endpoints, "tasks you will actually be given", refusal status table.
• New everything-dev#add-a-route: one complete copy-pasteable vertical slice — contract → Effect .effect() handler → useApiClient UI call → route file → typecheck → publish — with the failure modes the slice actually hits.
• All 20 existing skills across the three packages gain "The tasks you will actually be given" walkthroughs and "What comes back when it refuses/fails" error-word → action tables, grounded in the actual sources (verified per file). better-near-auth's client skill moved its 50-line action tables into references/client-actions.md.
• AGENTS.md intent block gains the two new skills.

Regression

• skill_family_served asserts the four package skill URLs return 200 with frontmatter; skill_md_mentions_router_loads_one_skill pins the router wording. Full go test ./ suite green.

Validation

• intent validate: 57 / 65 / 37 errors — identical to main baseline (all pre-existing); zero new errors from this change; intent stale reports needsReview: false everywhere.
• pnpm run typecheck ✓ · pnpm run lint clean (2 pre-existing warnings) · pnpm run build ui ✓ (13/3/6 skills in dist).
• Full HTTP regression suite green.
• Changesets: every-plugin (minor), everything-dev (minor), better-near-auth (minor).