[schemas] Make enhanced-thoughts self-contained for status columns

[lucifer]

Contribution Type

• Schema (/schemas)

What does this do?

Fixes a hidden cross-schema dependency in schemas/enhanced-thoughts/schema.sql. The upsert_thought RPC defined in that file writes to status and status_updated_at, but those columns are only added by schemas/workflow-status/migration.sql. docs/01-getting-started.md only instructs users to apply enhanced-thoughts, so following the getting-started path produces a broken RPC and capture_thought fails with:

column "status" of relation "thoughts" does not exist

This PR adds idempotent ADD COLUMN IF NOT EXISTS for status / status_updated_at (and the matching partial index) directly in enhanced-thoughts/schema.sql, so the RPC's dependencies live in the same file. Both schemas use IF NOT EXISTS, so users who already ran workflow-status are unaffected.

Requirements

None — pure SQL change in an existing schema file.

Checklist

• I've read CONTRIBUTING.md
• My contribution has a README.md with prerequisites, step-by-step instructions, and expected outcome — N/A, edit to existing schema
• My metadata.json has all required fields — N/A, no metadata change
• If my contribution depends on a skill or primitive, I declared it in metadata.json and linked it in the README — N/A
• I tested this on my own Open Brain instance (ran the equivalent ALTERs against my Supabase; capture_thought now succeeds)
• No credentials, API keys, or secrets are included

[alanshurafa]

Thanks for the contribution. This closes a real gap: enhanced-thoughts ships the upsert_thought RPC that writes status and status_updated_at, but those columns were only declared in schemas/workflow-status. Installing enhanced-thoughts alone would hit a missing-column error.

Checked the column definitions against schemas/workflow-status/migration.sql: the status / status_updated_at types and defaults and the idx_thoughts_status partial index are identical in both files, so applying either or both in any order leaves the same result. The inline comment documenting the dual definition is accurate. Recommend maintainer review.

— Alan (community reviewer; non-binding)

[justfinethanku]

Maintainer review complete. This is the smallest safe fix for the missing status/status_updated_at dependency in enhanced-thoughts, and Alan already verified the definitions match workflow-status.