Add guidance routing catalog

[ariobarin]

Summary

• add one machine-owned routing catalog for all 18 reviewed skills
• add compass.ps1 context status and task tracing with phase and mutation filters
• report estimated skill-core context cost and duplicate routing signals
• make doctor and cross-platform CI reject missing, stale, or invalid routing entries

Why

Skill descriptions remain owned by each SKILL.md, but selection needs a compact interface that can rank relevant guidance without loading every skill body. This PR adds only routing signals and filters, then makes complete catalog coverage enforceable.

Examples

• .\scripts\compass.ps1 context
• .\scripts\compass.ps1 context -Task "review PR 214" -Phase verify -Mutation public
• .\scripts\compass.ps1 context -Task "write a PRD" -Json

The current catalog contains about 18,802 estimated tokens across all skill cores. The PR-review fixture selects only pr-review-loop, about 923 estimated tokens.

Validation

• python scripts/test-context-routing.py
• python scripts/test-compass-architecture.py
• python scripts/test-skills-audit.py
• .\scripts\context-routing.ps1 -Check
• git diff --check
• .\scripts\doctor.ps1

[ariobarin]

Closing as incompatible with #290. This catalog is built around 18 active global skills that #290 retires. The branch remains available if routing is later reintroduced for a narrower non-global surface.