docs: standardize skill routing contracts

[kosako]

Summary

• standardize the 12 runtime skill descriptions around outcome, trigger mode, positive/negative routing boundaries, side effects, and composition
• add a catalog-derived runtime inventory and representative positive/negative routing queries
• preserve the merged diagnose/continuation/review/handoff authorization gates while clarifying neighboring routes
• tighten withheld-GitHub-content, mixed/unknown-review-author, ambiguous-defect, and third-party-policy boundaries
• rebind personal-asset-miner human approval to build sha256:635d2edf05f7a2a13623152276b548c23f6c3ac61fc08647c80de6745bd74c20 and artifact kind skill

Closes #215

Follow-up evaluation

• evaluate updated skill routing against post-deployment agent logs #221 remains open for post-deployment evaluation against actual Codex and Claude Code agent logs.
• It defines a pre-registered sampling plan, sanitized event schema, denominator-based metrics, target/cluster coverage, raw-log privacy boundaries, and separate follow-up issues for observed fixes.
• add eval schema validation and cross-skill routing suite #216 provides the routing suite that evaluate updated skill routing against post-deployment agent logs #221 will use as expected behavior.

Independent review

• Routing preflight: all three commits are authored by Codex, so the required reviewer is Claude.
• Restacked Fable review (41b7e7b..df5af80): must 0 / should 2 / nit 3, verdict WARNING.
• Fix commit: bf27b32.
• Final cumulative Fable re-review (41b7e7b..bf27b32): all five prior findings RESOLVED, no new regressions; must 0 / should 0 / nit 0, verdict APPROVE.

Validation

• all 17 scripts/tests/*.sh self-tests
• scripts/check-manifests.sh — 21 manifests passed
• scripts/check-injection.sh — expected medium runtime-state findings only; current build-bound human approval verified
• scripts/build.sh — 42 artifacts built
• scripts/register.sh — 42 registered, pending 0
• all 12 runtime frontmatter descriptions parse and remain within 1024 bytes (571–876 bytes)
• catalog query returns 12 unique artifact_kind=skill names
• personal-asset-miner catalog build ID exactly matches the approved hash and artifact kind
• staged public-safety gate passed for the review fix