fix(vault): recurse subfolders, skip empty stubs, parse block-list skills/metrics

[cordialApple]

Obsidian sync imported hand-authored notes as blank "Untitled" experiences and never read the real ones. Root causes, found against a real vault:

1. readVault read only the vault root, non-recursively — real notes in an experiences/ subfolder were never read; only empty [[wiki-link]] stub notes in the root imported (as blanks).
2. No empty-note guard — each stub minted a blank row that re-imported on every sync.
3. Frontmatter parser only understood inline skills: [...]; multi-line YAML block lists (skills as - name:/kind:, and metrics) were silently dropped.

Fix:

• walk the vault recursively, skipping dotfolders like .obsidian.
• planReconcile skips notes with no STAR content, so stubs no longer import or duplicate.
• Parse block-sequence skills/metrics from raw frontmatter; keep the inline form and add an H1 title fallback.

Verified end-to-end on the real vault: 18 experiences import fully populated (title, STAR, skills, metrics, tags); stubs skipped; 0 blanks. 767 unit tests green, typecheck clean.