Merge branch 'pr-1472' into integration/validation-batch

# Conflicts:
#	plugin/scripts/context-generator.cjs
#	plugin/scripts/mcp-server.cjs
#	plugin/scripts/worker-service.cjs
#	plugin/ui/viewer-bundle.js
#	src/cli/handlers/context.ts
#	src/services/sqlite/SessionStore.ts
#	src/services/sqlite/migrations/runner.ts
#	src/services/worker-service.ts
#	src/shared/SettingsDefaultsManager.ts

tests/services/sqlite/migration-runner.test.ts

@@ -22,6 +22,10 @@ interface TableColumnInfo {
   notnull: number;
 }
 
+interface IndexInfo {
+  name: string;
+}
+
 interface SchemaVersion {
   version: number;
 }
@@ -46,6 +50,11 @@ function getSchemaVersions(db: Database): number[] {
   return rows.map(r => r.version);
 }
 
+function getIndexNames(db: Database, table: string): string[] {
+  const rows = db.prepare(`PRAGMA index_list(${table})`).all() as IndexInfo[];
+  return rows.map(r => r.name);
+}
+
 describe('MigrationRunner', () => {
   let db: Database;
 
@@ -158,6 +167,43 @@ describe('MigrationRunner', () => {
     });
   });
 
+  describe('schema drift recovery for migration 24', () => {
+    it('should repair platform_source column and index even when version 24 is already recorded', () => {
+      db.run(`
+        CREATE TABLE IF NOT EXISTS schema_versions (
+          id INTEGER PRIMARY KEY,
+          version INTEGER UNIQUE NOT NULL,
+          applied_at TEXT NOT NULL
+        )
+      `);
+      db.prepare('INSERT INTO schema_versions (version, applied_at) VALUES (?, ?)').run(24, new Date().toISOString());
+
+      db.run(`
+        CREATE TABLE sdk_sessions (
+          id INTEGER PRIMARY KEY AUTOINCREMENT,
+          content_session_id TEXT UNIQUE NOT NULL,
+          memory_session_id TEXT UNIQUE,
+          project TEXT NOT NULL,
+          user_prompt TEXT,
+          started_at TEXT NOT NULL,
+          started_at_epoch INTEGER NOT NULL,
+          completed_at TEXT,
+          completed_at_epoch INTEGER,
+          status TEXT NOT NULL CHECK(status IN ('active','completed','failed'))
+        )
+      `);
+
+      const runner = new MigrationRunner(db);
+      expect(() => runner.runAllMigrations()).not.toThrow();
+
+      const columnNames = getColumns(db, 'sdk_sessions').map(column => column.name);
+      expect(columnNames).toContain('platform_source');
+
+      const indexNames = getIndexNames(db, 'sdk_sessions');
+      expect(indexNames).toContain('idx_sdk_sessions_platform_source');
+    });
+  });
+
   describe('issue #979 — old DatabaseManager version conflict', () => {
     it('should create core tables even when old migration versions 1-7 are in schema_versions', () => {
       // Simulate the old DatabaseManager having applied its migrations 1-7

tests/sqlite/sessions.test.ts

@@ -130,6 +130,38 @@ describe('Sessions Module', () => {
     });
   });
 
+  describe('platform_source', () => {
+    it('should default new sessions to claude when platformSource is omitted', () => {
+      const sessionId = createSDKSession(db, 'session-platform-1', 'project', 'prompt');
+      const session = getSessionById(db, sessionId);
+
+      expect(session?.platform_source).toBe('claude');
+    });
+
+    it('should preserve a non-default platform_source for legacy callers that omit platformSource', () => {
+      const sessionId = createSDKSession(db, 'session-platform-2', 'project', 'prompt', undefined, 'codex');
+      let session = getSessionById(db, sessionId);
+      expect(session?.platform_source).toBe('codex');
+
+      createSDKSession(db, 'session-platform-2', 'project', 'prompt');
+      session = getSessionById(db, sessionId);
+      expect(session?.platform_source).toBe('codex');
+    });
+
+    it('should reject explicit platform_source conflicts for the same session', () => {
+      createSDKSession(db, 'session-platform-3', 'project', 'prompt', undefined, 'codex');
+
+      expect(() => createSDKSession(
+        db,
+        'session-platform-3',
+        'project',
+        'prompt',
+        undefined,
+        'claude'
+      )).toThrow(/Platform source conflict/);
+    });
+  });
+
   describe('updateMemorySessionId', () => {
     it('should update memory_session_id for existing session', () => {
       const contentSessionId = 'content-session-update';