feat: flat spell frontmatter, full source-book titles, drop circle

Parser reads human-friendly flat keys (range, targets, castingTime, overcast
list, threshold/successes, ...) and expands them to SpellData; fixes
[object Object] range, empty targets/casting time and blank overcast rows.
SOURCE_BOOKS ids now match vault slugs and show full book titles.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

scripts/extract-spells-to-md.ts

@@ -1,3 +1,4 @@
+// DEPRECATED: one-off extractor that writes the old nested spell frontmatter. The vault now uses the flat format read by scripts/parsers/spell-parser.ts - do not run this over ObsidianNotes/spells.
 import { resolve, dirname } from 'node:path';
 import { readFileSync, writeFileSync, mkdirSync } from 'node:fs';
 import { fileURLToPath } from 'node:url';