Pre-implementation /runda round settled two open micro-calls before 4a,
both user-confirmed:
- IF [NOT] EXISTS admitted (no-op-that-succeeds-with-a-note), not
refused — a near-universal cross-vendor idiom (PostgreSQL, MySQL,
SQLite, Oracle 23ai), reclassified into scope rather than treated as
an engine-specific spelling. Touches §3/§4/§12/§13 (4a, 4c).
- INTEGER PRIMARY KEY maps to a plain int PK, not auto-increment;
serial stays the sole auto-increment type (§3).
README index updated in the same edit per the lockstep rule.