feat(context): add driver-discriminated connection schemas (#96)

* refactor(context): export and describe mapping shape schemas

* feat(context): add driver-schemas module with warehouse drivers

* feat(context): add metabase, looker, lookml driver schemas with mappings

* feat(context): add notion, dbt, metricflow driver schemas

* refactor(context): make connectionSchema a driver-discriminated union

* chore(context): re-export KtxConnectionConfig from project package

* docs(context): add connection driver schema plan

* chore(secrets): allowlist example credentials in driver-schemas fixtures

* test(cli): align metabase fixtures with required api_url field

The driver-discriminated union added in this branch now requires api_url
for metabase connections and a known driver for warehouses. Update slow
CLI test fixtures and assertions so they exercise the new schema:
- ingest.test-utils.ts: add api_url to the prod-metabase fixture.
- setup.test.ts: switch metabase fixture from 'url' to 'api_url'.
- local-scan-connectors.test.ts: invalid-driver/missing-driver tests now
  expect the schema error from loadKtxProject (parse-time rejection).

packages/cli/src/connection.test.ts

@@ -489,15 +489,17 @@ describe('runKtxConnection', () => {
   it('rejects unknown drivers with a helpful error', async () => {
     const projectDir = join(tempDir, 'project');
     await initKtxProject({ projectDir });
-    await writeConnections(projectDir, {
-      mystery: { driver: 'duckdb' },
-    });
+    await writeFile(
+      join(projectDir, 'ktx.yaml'),
+      'connections:\n  mystery:\n    driver: duckdb\n',
+      'utf-8',
+    );
     const io = makeIo();
 
     await expect(
       runKtxConnection({ command: 'test', projectDir, connectionId: 'mystery' }, io.io),
     ).resolves.toBe(1);
-    expect(io.stderr()).toContain('uses driver "duckdb"');
-    expect(io.stderr()).toContain('Supported:');
+    expect(io.stderr()).toContain('connections.mystery.driver');
+    expect(io.stderr()).toContain('postgres');
   });
 });

packages/cli/src/ingest.test-utils.ts

@@ -109,6 +109,7 @@ export async function writeWarehouseConfig(projectDir: string): Promise<void> {
       'connections:',
       '  prod-metabase:',
       '    driver: metabase',
+      '    api_url: https://metabase.example.test',
       '  warehouse_a:',
       '    driver: postgres',
       'ingest:',

packages/cli/src/local-scan-connectors.test.ts

@@ -92,7 +92,7 @@ describe('createKtxCliScanConnector', () => {
     expect(bigQueryMock.constructorInputs[0]).not.toHaveProperty('maxBytesBilled');
   });
 
-  it('throws for structural daemon-only fallback configs', async () => {
+  it('rejects daemon-only fallback driver configs at config parse time', async () => {
     await initKtxProject({ projectDir: tempDir });
     await writeFile(
       join(tempDir, 'ktx.yaml'),
@@ -105,14 +105,13 @@ describe('createKtxCliScanConnector', () => {
       ].join('\n'),
       'utf-8',
     );
-    const project = await loadKtxProject({ projectDir: tempDir });
 
-    await expect(createKtxCliScanConnector(project, 'warehouse')).rejects.toThrow(
-      'Connection "warehouse" uses driver "duckdb", which has no native standalone KTX scan connector',
+    await expect(loadKtxProject({ projectDir: tempDir })).rejects.toThrow(
+      /connections\.warehouse\.driver:.*Invalid discriminator value/,
     );
   });
 
-  it('throws a clear error when the connection block has no driver field', async () => {
+  it('rejects connection blocks with no driver field at config parse time', async () => {
     await initKtxProject({ projectDir: tempDir });
     await writeFile(
       join(tempDir, 'ktx.yaml'),
@@ -125,10 +124,9 @@ describe('createKtxCliScanConnector', () => {
       ].join('\n'),
       'utf-8',
     );
-    const project = await loadKtxProject({ projectDir: tempDir });
 
-    await expect(createKtxCliScanConnector(project, 'warehouse')).rejects.toThrow(
-      'Connection "warehouse" has no `driver` field in ktx.yaml',
+    await expect(loadKtxProject({ projectDir: tempDir })).rejects.toThrow(
+      /connections\.warehouse\.driver:.*Invalid discriminator value/,
     );
   });
 });

packages/cli/src/public-ingest.test.ts

@@ -85,7 +85,7 @@ describe('buildPublicIngestPlan', () => {
   it('plans warehouse connections as scan targets and source connections as source ingest targets', () => {
     const project = projectWithConnections({
       warehouse: { driver: 'postgres' },
-      prod_metabase: { driver: 'metabase' },
+      prod_metabase: { driver: 'metabase', api_url: 'https://metabase.example.com' },
       docs: { driver: 'notion' },
     });
 
@@ -745,7 +745,7 @@ describe('runKtxPublicIngest', () => {
     const io = makeIo();
     const project = projectWithConnections({
       warehouse: { driver: 'postgres' },
-      prod_metabase: { driver: 'metabase' },
+      prod_metabase: { driver: 'metabase', api_url: 'https://metabase.example.com' },
     });
     const runScan = vi.fn(async () => 1);
     const runIngest = vi.fn(async () => 0);

packages/cli/src/setup-sources.test.ts

@@ -1024,6 +1024,8 @@ describe('setup sources step', () => {
             databaseMappings: { '1': 'warehouse' },
             syncEnabled: { '1': true },
             syncMode: 'ALL',
+            selections: { collections: [], items: [] },
+            defaultTagNames: [],
           },
         },
         deps: {
@@ -1181,6 +1183,8 @@ describe('setup sources step', () => {
         databaseMappings: { '1': 'warehouse' },
         syncEnabled: { '1': true },
         syncMode: 'ALL',
+        selections: { collections: [], items: [] },
+        defaultTagNames: [],
       },
     });
     const testPrompts = prompts({

packages/cli/src/setup-sources.ts

@@ -451,6 +451,8 @@ function buildMetabaseConnection(args: KtxSetupSourcesArgs): KtxProjectConnectio
       databaseMappings: { [String(args.metabaseDatabaseId)]: args.sourceWarehouseConnectionId },
       syncEnabled: { [String(args.metabaseDatabaseId)]: true },
       syncMode: 'ALL',
+      selections: { collections: [], items: [] },
+      defaultTagNames: [],
     },
   };
 }

packages/cli/src/setup.test.ts

@@ -311,7 +311,7 @@ describe('setup status', () => {
         '    url: env:DATABASE_URL',
         '  metabase:',
         '    driver: metabase',
-        '    url: env:METABASE_URL',
+        '    api_url: https://metabase.example.test',
         '    api_key_ref: env:METABASE_API_KEY',
         '    warehouse_connection_id: warehouse',
         'llm:',