diff --git a/.specify/memory/constitution.md b/.specify/memory/constitution.md
index 77cf214..b4e8a8a 100644
--- a/.specify/memory/constitution.md
+++ b/.specify/memory/constitution.md
@@ -1,8 +1,8 @@
 <!--
 SYNC IMPACT REPORT
 ==================
-Version change: 1.1.1 → 1.2.0
-Ratified: 2026-05-01 | Last amended: 2026-05-03
+Version change: 1.2.0 → 1.3.0
+Ratified: 2026-05-01 | Last amended: 2026-05-06
 
 Principles introduced (first population from docs/CONSTITUTION.md):
   - §2  Architecture Principles (6 sub-principles)
@@ -94,10 +94,11 @@ The constitution acknowledges all three; the spec governs which is built.
 
 ### 2.5 Database abstraction
 
-PostgreSQL is the Phase 1 database. All DB access MUST go through a repository
-layer (one repository class per domain aggregate). Raw SQL or an ORM is
-acceptable, but no query logic MAY live outside a repository. This makes the
-planned PostgreSQL → SQLite refactor a repository-layer change only.
+PostgreSQL is the database. All DB access MUST go through a repository layer
+(one repository class per domain aggregate). Raw SQL or an ORM is acceptable,
+but no query logic MAY live outside a repository. No alternative database
+engine (SQLite, DuckDB, in-memory substitutes) MAY be used in integration
+tests — dialect differences mask production bugs.
 
 ### 2.6 No speculative abstraction
 
@@ -179,8 +180,11 @@ before any implementation step.
 ### 5.2 Test pyramid
 
 - **Unit tests** — pure logic, repository mocks, no I/O
-- **Integration tests** — API routes tested against a real (test) database
-  and a real (test) S3-compatible bucket (e.g. MinIO in Docker)
+- **Integration tests** — API routes tested against a real PostgreSQL instance
+  and a real S3-compatible bucket (e.g. MinIO in Docker). SQLite and other
+  in-memory database substitutes are **prohibited** — PostgreSQL-specific
+  behaviour (GROUP BY enforcement, JSON operators, constraint handling) MUST
+  be exercised by the test suite.
 - **E2E tests** — Angular + API, minimal set covering the core happy paths
 
 Unit and integration tests are required. E2E tests are best-effort in v1.
@@ -284,7 +288,8 @@ Phase 1 design is complete.
 | 1.1.0   | 2026-05-02 | Adopted into Spec Kit memory; fixed duplicate §4.3 → §4.4; strengthened "should" language to MUST/MUST NOT; added §9 Governance |
 | 1.1.1   | 2026-05-03 | Clarify that the only acceptable form of image transformation or editing is thumbnail generation                                |
 | 1.2.0   | 2026-05-03 | §2.4: Mark Phase 2 (JWT bearer auth) complete, reword phase status; §6: Add PyJWT to tech stack table; §8: Remove username/password auth from out-of-scope (now shipped) |
+| 1.3.0   | 2026-05-06 | §2.5: Remove planned PostgreSQL → SQLite refactor note; prohibit alternative database engines in integration tests. §5.2: Explicitly require PostgreSQL for integration tests; prohibit SQLite — a production HAVING/GROUP BY bug was masked by SQLite's permissive dialect. |
 
 ---
 
-**Version**: 1.2.0 | **Ratified**: 2026-05-01 | **Last Amended**: 2026-05-03
+**Version**: 1.3.0 | **Ratified**: 2026-05-01 | **Last Amended**: 2026-05-06