diff --git a/browse/test/security-adversarial-fixes.test.ts b/browse/test/security-adversarial-fixes.test.ts
new file mode 100644
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+++ b/browse/test/security-adversarial-fixes.test.ts
@@ -0,0 +1,137 @@
+/**
+ * Regression tests for the 4 adversarial findings fixed during /ship:
+ *
+ * 1. Canary stream-chunk split bypass — rolling-buffer detection across
+ *    consecutive text_delta / input_json_delta events.
+ * 2. Tool-output ensemble rule — single ML classifier >= BLOCK blocks
+ *    directly when the content is tool output (not user input).
+ * 3. escapeHtml quote escaping (unit-level check on the shape we expect).
+ * 4. snapshot command added to PAGE_CONTENT_COMMANDS.
+ *
+ * These tests pin the fixes so future refactors don't silently re-open
+ * the bypasses both adversarial reviewers (Claude + Codex) flagged.
+ */
+import { describe, test, expect } from 'bun:test';
+import * as fs from 'fs';
+import * as path from 'path';
+import { combineVerdict, THRESHOLDS } from '../src/security';
+import { PAGE_CONTENT_COMMANDS } from '../src/commands';
+
+const REPO_ROOT = path.resolve(__dirname, '..', '..');
+
+describe('canary stream-chunk split detection', () => {
+  test('detectCanaryLeak uses rolling buffer across consecutive deltas', () => {
+    // Pull in the function via dynamic require so we don't re-export it
+    // from sidebar-agent.ts (it's internal on purpose).
+    const agentSource = fs.readFileSync(
+      path.join(REPO_ROOT, 'browse', 'src', 'sidebar-agent.ts'),
+      'utf-8',
+    );
+    // Contract: detectCanaryLeak accepts an optional DeltaBuffer and
+    // uses .slice(-(canary.length - 1)) to retain a rolling tail.
+    expect(agentSource).toContain('DeltaBuffer');
+    expect(agentSource).toMatch(/text_delta\s*=\s*combined\.slice\(-\(canary\.length - 1\)\)/);
+    expect(agentSource).toMatch(/input_json_delta\s*=\s*combined\.slice\(-\(canary\.length - 1\)\)/);
+  });
+
+  test('canary context initializes deltaBuf', () => {
+    const agentSource = fs.readFileSync(
+      path.join(REPO_ROOT, 'browse', 'src', 'sidebar-agent.ts'),
+      'utf-8',
+    );
+    // The askClaude call site must construct the buffer so the rolling
+    // detection actually runs.
+    expect(agentSource).toContain("deltaBuf: { text_delta: '', input_json_delta: '' }");
+  });
+});
+
+describe('tool-output ensemble rule (single-layer BLOCK)', () => {
+  test('user-input context: single layer at BLOCK degrades to WARN', () => {
+    const result = combineVerdict([
+      { layer: 'testsavant_content', confidence: 0.95 },
+      { layer: 'transcript_classifier', confidence: 0 },
+    ]);
+    expect(result.verdict).toBe('warn');
+    expect(result.reason).toBe('single_layer_high');
+  });
+
+  test('tool-output context: single layer at BLOCK blocks directly', () => {
+    const result = combineVerdict(
+      [
+        { layer: 'testsavant_content', confidence: 0.95 },
+        { layer: 'transcript_classifier', confidence: 0, meta: { degraded: true } },
+      ],
+      { toolOutput: true },
+    );
+    expect(result.verdict).toBe('block');
+    expect(result.reason).toBe('single_layer_tool_output');
+  });
+
+  test('tool-output context still respects ensemble path when 2 agree', () => {
+    const result = combineVerdict(
+      [
+        { layer: 'testsavant_content', confidence: 0.80 },
+        { layer: 'transcript_classifier', confidence: 0.75 },
+      ],
+      { toolOutput: true },
+    );
+    expect(result.verdict).toBe('block');
+    expect(result.reason).toBe('ensemble_agreement');
+  });
+
+  test('tool-output context: below BLOCK threshold still WARN, not BLOCK', () => {
+    const result = combineVerdict(
+      [{ layer: 'testsavant_content', confidence: THRESHOLDS.WARN }],
+      { toolOutput: true },
+    );
+    expect(result.verdict).toBe('warn');
+  });
+});
+
+describe('sidepanel escapeHtml quote escaping', () => {
+  test('escapeHtml helper replaces double + single quotes', () => {
+    const src = fs.readFileSync(
+      path.join(REPO_ROOT, 'extension', 'sidepanel.js'),
+      'utf-8',
+    );
+    expect(src).toContain(".replace(/\"/g, '"')");
+    expect(src).toContain(".replace(/'/g, ''')");
+  });
+});
+
+describe('snapshot in PAGE_CONTENT_COMMANDS', () => {
+  test('snapshot is wrapped by untrusted-content envelope', () => {
+    expect(PAGE_CONTENT_COMMANDS.has('snapshot')).toBe(true);
+  });
+});
+
+describe('transcript classifier tool_output parameter', () => {
+  test('checkTranscript accepts optional tool_output', () => {
+    const src = fs.readFileSync(
+      path.join(REPO_ROOT, 'browse', 'src', 'security-classifier.ts'),
+      'utf-8',
+    );
+    expect(src).toContain('tool_output?: string');
+    expect(src).toContain('tool_output');
+    // Haiku prompt mentions tool_output
+    expect(src).toContain('tool_output');
+  });
+
+  test('sidebar-agent passes tool text to transcript on tool-result scan', () => {
+    const src = fs.readFileSync(
+      path.join(REPO_ROOT, 'browse', 'src', 'sidebar-agent.ts'),
+      'utf-8',
+    );
+    expect(src).toContain('tool_output: text');
+  });
+});
+
+describe('GSTACK_SECURITY_OFF kill switch', () => {
+  test('loadTestsavant honors env var early', () => {
+    const src = fs.readFileSync(
+      path.join(REPO_ROOT, 'browse', 'src', 'security-classifier.ts'),
+      'utf-8',
+    );
+    expect(src).toContain("process.env.GSTACK_SECURITY_OFF === '1'");
+  });
+});