fix: update DuckDB catalog compatibility for DuckLake 1.0 and Quack

- DuckLake 1.0 ships native Spark (MotherDuck) and Trino clients, so
  databricks.ducklake and trino.ducklake move from none → partial
- duckdb.ducklake also moves to partial so cross-engine pairs resolve
  correctly in the UI (was silently blocked by the none write-side)
- duckdb__duckdb pair override: remove the two outdated "single-engine
  only" statements; add Quack multi-writer note (beta v1.5, GA v2.0)
- duckdb REST write: replace vague "still maturing" with specific
  constraints (v1.4.2 for standard SQL, no UPDATE/DELETE on
  partitioned/sorted tables, merge-on-read only); add source URL
- Update test invariant: "ducklake none for all engines" → scoped to
  engines without a DuckLake client + new partial assertion for duckdb/
  trino/databricks

Author: b-per

src/data/compatibility.test.ts

@@ -162,9 +162,16 @@ describe('known facts', () => {
     }
   });
 
-  it('ducklake is none by default for all engines', () => {
-    for (const engine of ENGINES) {
-      expect(engineCatalogRules[engine].ducklake.support).toBe('none');
+  it('ducklake is none for engines without a DuckLake client', () => {
+    const noClient = ENGINES.filter(e => !(['duckdb', 'trino', 'databricks'] as string[]).includes(e));
+    for (const engine of noClient) {
+      expect(engineCatalogRules[engine].ducklake.support, `${engine} should have no ducklake support`).toBe('none');
+    }
+  });
+
+  it('ducklake is partial for engines with a DuckLake client', () => {
+    for (const engine of ['duckdb', 'trino', 'databricks'] as const) {
+      expect(engineCatalogRules[engine].ducklake.support, `${engine} should have partial ducklake support`).toBe('partial');
     }
   });
 

src/data/compatibility.ts

@@ -72,14 +72,24 @@ export const engineCatalogRules: Record<EngineId, EngineRule> = {
     hive:     { support: 'full', limitations: [] },
     s3tables: { support: 'none', limitations: [] },
     unity:    { support: 'full', limitations: [] },
-    ducklake: { support: 'none', limitations: [] },
+    ducklake: { support: 'partial', limitations: [
+      'Requires the DuckLake Spark client (maintained by MotherDuck)',
+      'DuckDB-backed catalog must be served via Quack for remote access — local DuckDB file not directly accessible',
+    ], sourceUrls: [
+      'https://ducklake.select/',
+      'https://motherduck.com/blog/announcing-ducklake-1-0-on-motherduck/',
+    ]},
     vendor_bridge: { support: 'none', limitations: [] },
   },
   duckdb: {
     glue:     { support: 'none', limitations: [] },
     rest:     { support: 'partial', limitations: [
-      'DuckDB Iceberg REST catalog write support added in v1.4.0 — still maturing',
+      'REST catalog write added in v1.4.0; standard SQL syntax (INSERT/UPDATE/DELETE) requires v1.4.2+',
+      'UPDATE and DELETE only supported on non-partitioned, non-sorted tables',
+      'Merge-on-read semantics only — no copy-on-write',
       'Not recommended for production write workloads',
+    ], sourceUrls: [
+      'https://duckdb.org/2025/11/28/iceberg-writes-in-duckdb',
     ]},
     hive:     { support: 'none', limitations: [] },
     s3tables: { support: 'partial', limitations: [
@@ -91,7 +101,13 @@ export const engineCatalogRules: Record<EngineId, EngineRule> = {
       'Known issues with HTTP 500 errors on some commit operations',
       'Not recommended for production write workloads',
     ]},
-    ducklake: { support: 'none', limitations: [] },
+    ducklake: { support: 'partial', limitations: [
+      'Requires the ducklake extension: INSTALL ducklake; LOAD ducklake;',
+      'Local DuckDB file catalog is single-writer; a Quack catalog server is required for concurrent or cross-engine writers',
+    ], sourceUrls: [
+      'https://ducklake.select/',
+      'https://duckdb.org/2026/05/12/quack-remote-protocol',
+    ]},
     vendor_bridge: { support: 'none', limitations: [] },
   },
   redshift: {
@@ -120,7 +136,12 @@ export const engineCatalogRules: Record<EngineId, EngineRule> = {
       'Trino connects to Unity Catalog via Iceberg REST, but write requires security mode adjustments and is not GA in OSS Trino',
       'Writes via Unity Catalog Iceberg REST create Managed Iceberg tables only — existing Delta tables are read-only via this interface',
     ]},
-    ducklake: { support: 'none', limitations: [] },
+    ducklake: { support: 'partial', limitations: [
+      'Requires a DuckLake Trino connector',
+      'DuckDB-backed catalog must be served via Quack for remote access — local DuckDB file not directly accessible',
+    ], sourceUrls: [
+      'https://ducklake.select/',
+    ]},
     vendor_bridge: { support: 'none', limitations: [] },
   },
   athena: {
@@ -189,8 +210,12 @@ export const pairOverrides: Partial<Record<PairKey, EngineRule>> = {
   'duckdb__duckdb': {
     glue:     { support: 'none', limitations: [] },
     rest:     { support: 'partial', limitations: [
-      'DuckDB REST catalog write support added in v1.4.0 — still maturing',
+      'REST catalog write added in v1.4.0; standard SQL syntax (INSERT/UPDATE/DELETE) requires v1.4.2+',
+      'UPDATE and DELETE only supported on non-partitioned, non-sorted tables',
+      'Merge-on-read semantics only — no copy-on-write',
       'Not recommended for production workloads',
+    ], sourceUrls: [
+      'https://duckdb.org/2025/11/28/iceberg-writes-in-duckdb',
     ]},
     hive:     { support: 'none', limitations: [] },
     s3tables: { support: 'partial', limitations: [
@@ -203,9 +228,12 @@ export const pairOverrides: Partial<Record<PairKey, EngineRule>> = {
       'Not recommended for production write workloads',
     ]},
     ducklake: { support: 'partial', limitations: [
-      'DuckLake stores catalog metadata in a DuckDB database file — not accessible by other engines',
       'Requires the ducklake extension: INSTALL ducklake; LOAD ducklake;',
-      'Designed for single-engine local use cases — not suitable for cross-platform sharing',
+      'Local DuckDB file catalog is single-writer only',
+      'Concurrent multi-writer access requires a Quack catalog server (beta in v1.5, GA planned with DuckDB v2.0)',
+    ], sourceUrls: [
+      'https://ducklake.select/2026/04/13/ducklake-10/',
+      'https://duckdb.org/2026/05/12/quack-remote-protocol',
     ]},
     vendor_bridge: { support: 'none', limitations: [] },
   },