fix: align root write context schema metadata

[Joncallim]

Scope

Aligns the protected write-context table’s physical PostgreSQL metadata with its Drizzle declaration.

• Names the primary key, unique constraint, positive-value checks, and foreign keys explicitly and identically on both sides.
• Preserves pg_catalog.clock_timestamp() for entered_at; Drizzle now expresses the same wall-clock default rather than now() / transaction-start time.
• Adds a focused parity contract covering default, constraints, foreign keys, and restrict deletes.

Compatibility

Migration 0027 is unshipped in this stack, so the corrected DDL applies directly on fresh and populated upgrade paths; no applied-database constraint rename is needed. No constraints are dropped or rebuilt.

Validation

• PostgreSQL 16 temporary, rolled-back catalog probe confirmed the prior generated names and clock_timestamp() default
• npm test -- --run __tests__/project-root-reconciliation.test.ts (21 passed)
• npm test (1,630 passed, 19 skipped)
• npx eslint --max-warnings=0 db/schema.ts __tests__/project-root-reconciliation.test.ts
• npx tsc --noEmit
• npm run build
• git diff --check