feat(database): add getTablePage() for paginated table reads

Add getTablePage() to DatabaseAdapter (default no-op) and implement
in SQLiteAdapter with parameterized LIMIT/OFFSET. Wire into
MigrationManager.getBatch() to replace placeholder stubs.

Author: StackMemory Bot (CLI)

src/core/database/database-adapter.ts

@@ -204,6 +204,18 @@ export abstract class DatabaseAdapter {
     callback: (adapter: DatabaseAdapter) => Promise<void>
   ): Promise<void>;
 
+  // Paginated table reads (for migration)
+  async getTablePage(
+    table: 'frames' | 'events' | 'anchors',
+    offset: number,
+    limit: number
+  ): Promise<any[]> {
+    void table;
+    void offset;
+    void limit;
+    return []; // Default no-op; overridden in concrete adapters
+  }
+
   // Export/Import for migration
   abstract exportData(
     tables: string[],

src/core/database/migration-manager.ts

@@ -453,25 +453,12 @@ export class MigrationManager extends EventEmitter {
     const safeLimit = Math.max(1, Math.min(limit, 10000));
     const safeOffset = Math.max(0, offset);
 
-    // TODO: Use these options when adapter methods support pagination
-    void safeLimit;
-    void safeOffset;
-
-    switch (table) {
-      case 'frames':
-        // This would need to be implemented in the adapter
-        return []; // Placeholder
-      case 'events':
-        return []; // Placeholder
-      case 'anchors':
-        return []; // Placeholder
-      default:
-        throw new DatabaseError(
-          `Unsupported table: ${table}`,
-          ErrorCode.DB_QUERY_FAILED,
-          { table }
-        );
-    }
+    const validTable = table as 'frames' | 'events' | 'anchors';
+    return this.config.sourceAdapter.getTablePage(
+      validTable,
+      safeOffset,
+      safeLimit
+    );
   }
 
   private async migrateBatch(table: string, batch: any[]): Promise<void> {

src/core/database/sqlite-adapter.ts

@@ -1767,6 +1767,33 @@ export class SQLiteAdapter extends FeatureAwareDatabaseAdapter {
     });
   }
 
+  async getTablePage(
+    table: 'frames' | 'events' | 'anchors',
+    offset: number,
+    limit: number
+  ): Promise<any[]> {
+    if (!this.db)
+      throw new DatabaseError(
+        'Database not connected',
+        ErrorCode.DB_CONNECTION_FAILED
+      );
+
+    const safeLimit = Math.max(1, Math.min(limit, 10000));
+    const safeOffset = Math.max(0, offset);
+    const allowedTables = ['frames', 'events', 'anchors'] as const;
+    if (!(allowedTables as readonly string[]).includes(table)) {
+      throw new DatabaseError(
+        `Invalid table name: ${table}`,
+        ErrorCode.DB_QUERY_FAILED,
+        { table }
+      );
+    }
+
+    return this.db
+      .prepare(`SELECT * FROM ${table} ORDER BY rowid LIMIT ? OFFSET ?`)
+      .all(safeLimit, safeOffset);
+  }
+
   async vacuum(): Promise<void> {
     if (!this.db)
       throw new DatabaseError(