feat(optimization): implement manifest-driven extraction pipeline

- Implement `extract.ts` with robust character-aware parsing for snippets and tools.
- Consolidate research dependencies by moving `@ax-llm/ax` to root `optionalDependencies`.
- Relocate evaluation logic from `packages/core` to `scripts/optimization/lib/evals` to keep the production core lean.
- Add `optimization_targets` to `data/manifest.json` as the single source of truth for the pipeline.
- Implement comprehensive unit tests for extraction and variable masking with 100% pass rate.
- Update global config and linting rules to support the new optimization infrastructure.

scripts/optimization/extract.test.ts

@@ -0,0 +1,99 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import * as fs from 'node:fs';
+import { runExtraction } from './extract.js';
+
+vi.mock('node:fs');
+
+describe('extraction script', () => {
+  const mockManifest = {
+    data_inventory: {
+      optimization_targets: {
+        snippets: ['renderCoreMandates'],
+      },
+      tools: {
+        read_file: {},
+      },
+    },
+  };
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vi.mocked(fs.existsSync).mockReturnValue(true);
+    vi.mocked(fs.readFileSync).mockImplementation((path) => {
+      if (typeof path !== 'string') return '';
+      if (path.includes('manifest.json')) return JSON.stringify(mockManifest);
+
+      // Mock snippets.ts
+      if (path.includes('snippets.ts')) {
+        return `
+          export function renderCoreMandates(options: any): string {
+            const foo = "Ignore me";
+            return \`# Core Mandate Instruction \${USER_VAR}\`.trim();
+          }
+        `;
+      }
+
+      // Mock gemini-3.ts
+      if (path.includes('gemini-3.ts')) {
+        return `
+  read_file: {
+    description: 'Read file description.',
+  },
+`;
+      }
+
+      // Mock dynamic helpers
+      if (path.includes('dynamic-declaration-helpers.ts')) {
+        return `
+          return \`This tool executes a given shell command as \\\`bash -c <command>\\\`. \${backgroundInstructions}\`;
+          name: EXIT_PLAN_MODE_TOOL_NAME,
+          description: 'Exit Plan Mode.',
+          name: ACTIVATE_SKILL_TOOL_NAME,
+          description: \`Activate skill.\`,
+        `;
+      }
+      return '';
+    });
+  });
+
+  it('should extract snippets correctly (Step 1)', async () => {
+    const targets = await runExtraction();
+    const snippet = targets.find((t) => t.id === 'snippets:renderCoreMandates');
+    expect(snippet).toBeDefined();
+    expect(snippet?.originalText).toBe(
+      '# Core Mandate Instruction ${USER_VAR}',
+    );
+    expect(snippet?.maskedText).toContain('[[GCLI_VAR_0]]');
+  });
+
+  it('should extract tools correctly (Step 2)', async () => {
+    const targets = await runExtraction();
+    const tool = targets.find((t) => t.id === 'gemini3:read_file:description');
+    expect(tool).toBeDefined();
+    expect(tool?.originalText).toBe('Read file description.');
+  });
+
+  it('should extract dynamic helpers correctly (Step 3)', async () => {
+    const targets = await runExtraction();
+    const shell = targets.find((t) => t.id === 'shell:darwin:description');
+    expect(shell).toBeDefined();
+    expect(shell?.maskedText).toContain('[[GCLI_VAR_0]]');
+
+    const exitPlan = targets.find((t) => t.id === 'exit_plan_mode:description');
+    expect(exitPlan?.originalText).toBe('Exit Plan Mode.');
+  });
+
+  it('should write targets.json to the correct directory', async () => {
+    await runExtraction();
+    expect(fs.writeFileSync).toHaveBeenCalledWith(
+      expect.stringContaining('targets.json'),
+      expect.any(String),
+    );
+  });
+});