fs.realpathSync(vaultPath) recomputed once per wikilink #373

Location: src/storage/wikilink.ts:207 (from resolveWikilinkRoadmap :382)

resolveWikilinkTarget calls realpathSync(vaultPath) on every invocation; resolveWikilinkRoadmap loops all sections x links, so the vault root is canonicalized N times for an N-link roadmap.

Fix: Hoist realpathSync(vaultPath) into resolveWikilinkRoadmap and pass the resolved root in.

From the 2026-10-10 codebase audit sweep (CODEBASE_AUDIT.md).