feat(web): enable personal kits and collections APIs in production

[mrgoonie]

Summary

• Set SKILLX_PERSONAL_KITS_API and SKILLX_COLLECTIONS_API to "1" in apps/web/wrangler.jsonc. Both are needed by Personal-kit API gaps for AgentKit kit publish/sync #88 (personal kits in production) and [Phase 3] Personal kits, installer, lockfile and multi-device sync #35 (collections install smoke).
• Fix the collections flag comment, which pointed at migration 0018: collection lineage is 0019 since the migration renumber.
• Update docs/deployment-guide.md to describe the production flag state.

Production preconditions (done)

• Took a D1 Time Travel bookmark before migrating; it is stored in the owner's secret vault.
• Applied migrations 0018 (registry_publishing) and 0019 (collection_revision_lineage) remotely.
• Deployed main at fbd0333 (version 27d34bce) with both flags still "0". Smoke: /, search and registry keys return 200; /api/v1/collections returns 404 while the flag is off.

Rollback

For either API, set its flag back to "0" and redeploy. Its routes then return 404, and no data is touched.

Test plan

• Config-only change: no code paths change. The flag-on behaviour is covered by the existing route tests, which set the env per test.
• After merge: deploy, then run the personal kits smoke (CAS, private access, rollback) and the collections smoke.

Docs impact: docs/deployment-guide.md updated (flag state).

🤖 Generated with Claude Code

[mrgoonie]

Production D1 migration evidence (2026-10-20 09:40 +07): wrangler d1 migrations list skillx-db --remote → No migrations to apply!; d1_migrations contains 0015_personal_kits, 0016_personal_kit_proposals, 0018_registry_publishing, 0019_collection_revision_lineage. Head 71b5a22 adds the migration prerequisites and rollback to the flag comments and the deployment guide.