chore: sync metaschema-schema from constructive-db

Summary

Bulk sync of packages/metaschema-schema from the canonical copy in constructive-io/constructive-db/pgpm-modules/metaschema-schema. This repo had fallen significantly behind. Key changes:

Dead table removal:

• Deleted procedure, limit_function, and rls_function tables (deploy, revert, verify, combined SQL, pgpm.plan)

New table:

• Added default_privilege for declarative ALTER DEFAULT PRIVILEGES (grant/revoke on tables, functions, sequences)

Column renames (breaking):

• role_name → grantee_name in policy, table_grant, view_grant
• template → policy_type in policy

New columns:

• is_grant boolean on table_grant and view_grant (enables revoke records)
• smart_tags, category, module, scope, tags added to index, trigger, check_constraint, foreign_key_constraint, primary_key_constraint, unique_constraint, field

Other schema changes:

• database table: removed schema_name and private_schema_name columns
• table unique constraint widened to (database_id, schema_id, name) (was (database_id, name))
• field.category type changed from field_category to object_category; field_category enum removed
• object_category enum now includes module and app values
• databases_table_unique_name_idx now includes schema_id

Updates since last revision

• Updated test snapshots for metaschema-modules and services packages to reflect schema changes:
  • services.test.ts.snap: removed schema_name and private_schema_name from database snapshot (columns were dropped)
  • modules.test.ts.snap: updated constraint counts (72600→67416, 102535→96840) due to dead table removal; re-sorted sessions_module snapshot block (content unchanged, just ordering)
• CI now fully green (22/22 checks passing)

Review & Testing Checklist for Human

• Verify rls_function deletion is intentional — the conversation only explicitly mentioned procedure and limit_function as dead code. Confirm rls_function is also dead in constructive-db (it appears to have been removed there previously, but worth double-checking).
• Verify column renames don't break downstream consumers — role_name → grantee_name and template → policy_type are breaking changes. Check that no other packages in this repo or downstream consumers reference the old column names.
• Verify field_category type removal — confirm no downstream code in pgpm-modules or consumers references metaschema_public.field_category directly.
• Verify combined SQL (metaschema-schema--0.15.5.sql) is consistent with the individual deploy files — this was synced as a whole file from constructive-db, not regenerated locally.
• Spot-check snapshot constraint count changes — the constraint counts dropped significantly (e.g. 72600→67416). This is expected from dead table removal, but worth a sanity check that no live tables were accidentally removed.

Notes

• This is a one-way sync from constructive-db to pgpm-modules. Any divergent changes in pgpm-modules have been overwritten.
• The sync was done by copying deploy/, revert/, verify/, pgpm.plan, and sql/metaschema-schema--0.15.5.sql from constructive-db.
• Companion PRs:
  • constructive-io/constructive-db#548 (removes dead tables + regenerates codegen)
  • chore: remove dead procedure and limit_function table exports constructive#761 (removes dead table exports from pgpm export config)
• Requested by: @pyramation
• Link to Devin run