fix(cli): carry the catalog's recommended field under metadata, where Claude Code does not warn

[blafourcade]

🎯 What & why

claude plugin validate warned plugins[7].recommended: Unknown field 'recommended'. Claude Code ignores it at load time on our source catalog and on every claude build, and #795 made CI run that validation on each pull request. A warning that never goes away trains everyone to ignore the next one. The field is ours: aidd setup and plugin search --recommended draw the curated install path from it.

🛠️ How it works

• Measured against Claude Code's validator with a throwaway marketplace: a plugin entry's metadata object is the one placement that passes silently (metadata.recommended, any content). category, tags, keywords pass too but are official fields with their own meaning; x-recommended, a top-level x-aidd, and metadata.* at marketplace level all warn.
• The field moves under each entry's metadata: the source catalog (8 entries), the five fixtures, assets/schemas/claude-marketplace-manifest.json, scripts/validate-json.mjs, the parser in distribution/domain/catalog.ts (which reads no other spelling), and the claude-style catalog every build writes (tools/domain/marketplace-catalog.ts).
• The nine-cell golden is re-baselined for claude and cursor, whose marketplace-mode catalogs now carry metadata.recommended; the seven other cells are byte-identical.
• docs/CREATE_PLUGIN.md says where the field goes and why.

🧪 How to verify

• claude plugin validate . at the repository root → ✔ Validation passed, no warning.
• node scripts/check-claude-accepts-build.cjs → ✔ Validation passed, no warning (was "passed with warnings").
• cd cli && pnpm vitest run tests/contexts/distribution/domain/catalog.unit.test.ts tests/contexts/tools/domain/marketplace-catalog.unit.test.ts
• Red first: expected false to be true (parser), expected undefined to strictly equal { recommended: false } (builder).
• Locally green: typecheck, lint, arch (126), knip, unit+integration (4282), e2e (297, golden included), build, smoke (FAIL 0), repository scripts (441), type honesty, doc checks.

⚠️ Heads-up

• A CLI older than this one reads a catalog carrying the new spelling as "nothing recommended": setup then proposes no curated set until aidd update. The CLI and the catalog release together, so only a user pinning an old CLI against the new marketplace ref sees it.
• The parser reads one spelling on purpose; a third-party catalog written with a top-level recommended (none known) is read as not recommended.

🔗 Linked issue

Closes #800

✅ I certify

• I DO CERTIFY I READ EACH LINE OF THE PULL REQUEST BECAUSE I AM A SOFTWARE ENGINEER, NOT A AI PUPPY.

🤖 Generated with Claude Code

https://claude.ai/code/session_011x4ms5qcGuZgYhCxfdHMUb