fix: scope checkPaths to ROUTER.md only

[Taegost]

What

Filters the claims array passed to checkPaths so it only includes claims extracted from ROUTER.md. This eliminates false MISSING_PATH errors from context docs, pattern files, and tool config files where backtick-wrapped strings are general-purpose inline code, not path declarations.

Why

Fixes #79 — checkPaths was extracting every backtick-wrapped string from all scaffold markdown files and attempting to resolve each as a file path. Strings like csi.kubeletRootDir: /var/lib/kubelet, argocd.argoproj.io/sync-wave, and 192.168.5.0/24 were flagged as MISSING_PATH errors (-10 points each), producing a drift score of 0/100 on real-world scaffolds.

Changes

• src/drift/index.ts — Added basename import; filtered allClaims to only ROUTER.md before passing to checkPaths
• test/public-api.test.ts — Added 3 integration tests verifying the scoping behavior
• CHANGELOG.md — Added entry under [Unreleased]

Verification

Tested against https://github.com/Taegost/homelab-k8s branch feat/mex-integration (the repo where the issue was reported):

Metric	Before	After
Score	0/100	79/100
Errors	18	0
Warnings	7	7

The remaining 7 warnings are BROKEN_LINK issues in patterns/INDEX.md from a different checker — unchanged by this fix.

🤖 Generated with Claude Code

[theDakshJaitly]

Thanks for the clear fix and for validating it against the real scaffold that surfaced #79.

I reviewed the diff and verified locally with:

• npm test -- test/public-api.test.ts test/checkers.test.ts test/claims.test.ts
• npm run typecheck
• npm run build

Scoping checkPaths to ROUTER.md looks like the right behavior for now: it preserves path validation where the scaffold declares navigation, while avoiding noisy MISSING_PATH errors from inline config values in context and pattern docs.

LGTM.