chore: apply Anthropic best practices to all skills (v1.4.2)

- Add `allowed-tools` frontmatter to all 10 SKILL.md files for tool pre-approval
- Soften kepano/obsidian-skills dependency in 4 skills (canvas, obsidian-bases, obsidian-markdown, wiki-ingest) — now recommends if installed, doesn't require
- Soften banana-claude dependency in canvas skill
- Improve trigger descriptions for defuddle (+4 phrases) and obsidian-markdown (+5 phrases)
- Remove docs/superpowers/plans/ (contained private paths)
- Gitignore claude-obsidian-archive/ and _attachments/
- Bump version to 1.4.2

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

skills/wiki-lint/SKILL.md

@@ -5,6 +5,7 @@ description: >
   missing cross-references, frontmatter gaps, and empty sections. Creates or updates
   Dataview dashboards. Generates canvas maps. Triggers on: "lint", "health check",
   "clean up wiki", "check the wiki", "wiki maintenance", "find orphans", "wiki audit".
+allowed-tools: Read Write Edit Glob Grep
 ---
 
 # wiki-lint: Wiki Health Check