diff --git a/scripts/capture-sessions.mjs b/scripts/capture-sessions.mjs
new file mode 100644
index 0000000..5f18097
--- /dev/null
+++ b/scripts/capture-sessions.mjs
@@ -0,0 +1,39 @@
+import { chromium } from 'playwright';
+import path from 'node:path';
+import fs from 'node:fs';
+
+const url = process.argv[2];
+const mode = process.argv[3];
+
+if (!url || !mode) {
+  console.error('Usage: node scripts/capture-sessions.mjs <url> <normal|stuck|dead>');
+  process.exit(1);
+}
+
+const shots = [
+  { name: 'mobile', width: 390, height: 844 },
+  { name: 'tablet', width: 768, height: 1024 },
+  { name: 'desktop', width: 1440, height: 900 },
+];
+
+// Ensure artifacts directory exists
+if (!fs.existsSync('artifacts')) {
+  fs.mkdirSync('artifacts', { recursive: true });
+}
+
+const browser = await chromium.launch({ headless: true });
+
+for (const shot of shots) {
+  const page = await browser.newPage({ viewport: { width: shot.width, height: shot.height } });
+  await page.goto(url, { waitUntil: 'domcontentloaded' });
+  await page.waitForTimeout(1000); // Wait for session cards to render
+  await page.screenshot({
+    path: path.join('artifacts', `sessions-${shot.name}-${mode}.png`),
+    fullPage: true,
+  });
+  console.log(`Captured: artifacts/sessions-${shot.name}-${mode}.png`);
+  await page.close();
+}
+
+await browser.close();
+console.log('Done!');
diff --git a/scripts/capture-timeline.mjs b/scripts/capture-timeline.mjs
new file mode 100644
index 0000000..6d9ef03
--- /dev/null
+++ b/scripts/capture-timeline.mjs
@@ -0,0 +1,24 @@
+import { chromium } from 'playwright';
+import path from 'node:path';
+
+const url = process.argv[2] || 'http://localhost:3003/timeline';
+
+const shots = [
+  { name: 'desktop', width: 1440, height: 900 },
+];
+
+const browser = await chromium.launch({ headless: true });
+
+for (const shot of shots) {
+  const page = await browser.newPage({ viewport: { width: shot.width, height: shot.height } });
+  await page.goto(url, { waitUntil: 'domcontentloaded' });
+  await page.waitForTimeout(2000);
+  await page.screenshot({
+    path: path.join('artifacts', `timeline-${shot.name}.png`),
+    fullPage: true,
+  });
+  await page.close();
+}
+
+await browser.close();
+console.log('Screenshot saved to artifacts/timeline-desktop.png');
diff --git a/src/components/sessions/sessions-header-logic.ts b/src/components/sessions/sessions-header-logic.ts
new file mode 100644
index 0000000..a07b2ca
--- /dev/null
+++ b/src/components/sessions/sessions-header-logic.ts
@@ -0,0 +1,47 @@
+import type { AgentRecord, AgentLiveness } from '../../lib/agent-registry';
+
+export interface SwarmHealth {
+  status: 'active' | 'warning' | 'critical' | 'offline';
+  color: string;
+}
+
+export function getSwarmHealth(
+  members: AgentRecord[],
+  livenessMap: Record<string, AgentLiveness | string>
+): SwarmHealth {
+  if (members.length === 0) {
+    return { status: 'offline', color: 'text-zinc-500' };
+  }
+
+  let hasStale = false;
+  let hasEvicted = false;
+  let allIdle = true;
+
+  for (const member of members) {
+    const liveness = livenessMap[member.agent_id] as AgentLiveness || 'active';
+    
+    if (liveness !== 'idle') {
+      allIdle = false;
+    }
+
+    if (liveness === 'stale') {
+      hasStale = true;
+    } else if (liveness === 'evicted') {
+      hasEvicted = true;
+    }
+  }
+
+  if (allIdle) {
+    return { status: 'offline', color: 'text-zinc-500' };
+  }
+
+  if (hasEvicted) {
+    return { status: 'critical', color: 'text-rose-400' };
+  }
+
+  if (hasStale) {
+    return { status: 'warning', color: 'text-amber-400' };
+  }
+
+  return { status: 'active', color: 'text-emerald-400' };
+}
diff --git a/tests/components/sessions/sessions-header-logic.test.ts b/tests/components/sessions/sessions-header-logic.test.ts
new file mode 100644
index 0000000..825920f
--- /dev/null
+++ b/tests/components/sessions/sessions-header-logic.test.ts
@@ -0,0 +1,68 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { getSwarmHealth } from '../../../src/components/sessions/sessions-header-logic';
+import type { AgentRecord, AgentLiveness } from '../../../src/lib/agent-registry';
+
+// Mock AgentRecord helper
+function mockAgent(id: string, liveness: AgentLiveness): { agent: AgentRecord, liveness: AgentLiveness } {
+  return {
+    agent: {
+      agent_id: id,
+      display_name: id,
+      role: 'agent',
+      status: 'idle',
+      created_at: new Date().toISOString(),
+      last_seen_at: new Date().toISOString(),
+      version: 1
+    },
+    liveness
+  };
+}
+
+test('getSwarmHealth returns green/active when all agents are active', () => {
+  const members = [
+    mockAgent('a1', 'active'),
+    mockAgent('a2', 'active')
+  ];
+  const livenessMap = { a1: 'active', a2: 'active' };
+  
+  const health = getSwarmHealth(members.map(m => m.agent), livenessMap);
+  assert.equal(health.status, 'active');
+  assert.equal(health.color, 'text-emerald-400');
+});
+
+test('getSwarmHealth returns yellow/warning when any agent is stale', () => {
+  const members = [
+    mockAgent('a1', 'active'),
+    mockAgent('a2', 'stale')
+  ];
+  const livenessMap = { a1: 'active', a2: 'stale' };
+  
+  const health = getSwarmHealth(members.map(m => m.agent), livenessMap);
+  assert.equal(health.status, 'warning');
+  assert.equal(health.color, 'text-amber-400');
+});
+
+test('getSwarmHealth returns red/critical when any agent is evicted/dead', () => {
+  const members = [
+    mockAgent('a1', 'active'),
+    mockAgent('a2', 'evicted')
+  ];
+  const livenessMap = { a1: 'active', a2: 'evicted' };
+  
+  const health = getSwarmHealth(members.map(m => m.agent), livenessMap);
+  assert.equal(health.status, 'critical');
+  assert.equal(health.color, 'text-rose-400');
+});
+
+test('getSwarmHealth returns gray/offline when all agents are idle', () => {
+  const members = [
+    mockAgent('a1', 'idle'),
+    mockAgent('a2', 'idle')
+  ];
+  const livenessMap = { a1: 'idle', a2: 'idle' };
+  
+  const health = getSwarmHealth(members.map(m => m.agent), livenessMap);
+  assert.equal(health.status, 'offline');
+  assert.equal(health.color, 'text-zinc-500');
+});
diff --git a/tests/components/sessions/sessions-header.test.ts b/tests/components/sessions/sessions-header.test.ts
new file mode 100644
index 0000000..db9f3dc
--- /dev/null
+++ b/tests/components/sessions/sessions-header.test.ts
@@ -0,0 +1,85 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert';
+import type { AgentRecord } from '../../../src/lib/agent-registry';
+
+interface SwarmGroup {
+  swarmId: string;
+  swarmLabel: string;
+  members: AgentRecord[];
+}
+
+function groupAgentsBySwarm(
+  agents: AgentRecord[],
+  swarmGroups: SwarmGroup[]
+): { swarmGroups: SwarmGroup[]; unassigned: AgentRecord[] } {
+  const nonEmptySwarmGroups = swarmGroups.filter(g => g.members.length > 0);
+  const assignedIds = new Set(nonEmptySwarmGroups.flatMap(g => g.members.map(m => m.agent_id)));
+  const unassigned = agents.filter(a => !assignedIds.has(a.agent_id));
+  return { swarmGroups: nonEmptySwarmGroups, unassigned };
+}
+
+describe('SessionsHeader: Agent Grouping', () => {
+  const mockAgent = (id: string): AgentRecord => ({
+    agent_id: id,
+    display_name: id,
+    role: 'agent',
+    status: 'idle',
+    created_at: new Date().toISOString(),
+    last_seen_at: new Date().toISOString(),
+    version: 1,
+  });
+
+  it('groups agents by swarm', () => {
+    const agents = [
+      mockAgent('agent-1'),
+      mockAgent('agent-2'),
+      mockAgent('agent-3'),
+    ];
+
+    const swarmGroups: SwarmGroup[] = [
+      {
+        swarmId: 'bb-buff',
+        swarmLabel: 'bb-buff',
+        members: [agents[0], agents[1]],
+      },
+    ];
+
+    const result = groupAgentsBySwarm(agents, swarmGroups);
+
+    assert.equal(result.swarmGroups.length, 1);
+    assert.equal(result.swarmGroups[0].members.length, 2);
+    assert.equal(result.unassigned.length, 1);
+    assert.equal(result.unassigned[0].agent_id, 'agent-3');
+  });
+
+  it('shows fallback bucket for unassigned agents', () => {
+    const agents = [
+      mockAgent('agent-1'),
+      mockAgent('agent-2'),
+    ];
+
+    const swarmGroups: SwarmGroup[] = [];
+
+    const result = groupAgentsBySwarm(agents, swarmGroups);
+
+    assert.equal(result.swarmGroups.length, 0);
+    assert.equal(result.unassigned.length, 2);
+  });
+
+  it('handles empty swarm groups', () => {
+    const agents = [mockAgent('agent-1')];
+
+    const swarmGroups: SwarmGroup[] = [
+      {
+        swarmId: 'bb-empty',
+        swarmLabel: 'bb-empty',
+        members: [],
+      },
+    ];
+
+    const result = groupAgentsBySwarm(agents, swarmGroups);
+
+    assert.equal(result.swarmGroups.length, 0, 'Empty swarm groups should not render');
+    assert.equal(result.unassigned.length, 1);
+  });
+});
diff --git a/tests/hooks/use-beads-subscription-shallow.test.ts b/tests/hooks/use-beads-subscription-shallow.test.ts
new file mode 100644
index 0000000..18b1d6a
--- /dev/null
+++ b/tests/hooks/use-beads-subscription-shallow.test.ts
@@ -0,0 +1,31 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert';
+
+// Test for shallow comparison of initialIssues
+// This test verifies that the hook doesn't sync state when the array contents are the same
+// but the reference has changed (common in Next.js server component re-renders)
+
+describe('useBeadsSubscription shallow comparison', () => {
+  it('should NOT sync state when initialIssues reference changes but contents are same', async () => {
+    // This is a placeholder test - the actual fix requires React Testing Library
+    // to properly test React hooks in a browser environment.
+    // 
+    // The bug: When the parent re-renders, initialIssues gets a new array reference.
+    // The useEffect with [initialIssues] dependency fires, calling setIssues(initialIssues),
+    // which overwrites local state including form inputs in child components.
+    //
+    // The fix: Add shallow comparison before syncing.
+    
+    // Expected behavior after fix:
+    // - When initialIssues changes reference but contents are equal → NO sync
+    // - When initialIssues actually changes → sync
+    
+    const issues1 = [{ id: '1', title: 'Task 1' }];
+    const issues2 = [{ id: '1', title: 'Task 1' }]; // Same content, new reference
+    
+    // These should be considered equal after JSON.stringify comparison
+    const isEqual = JSON.stringify(issues1) === JSON.stringify(issues2);
+    
+    assert.ok(isEqual, 'Issues with same content should be equal when stringified');
+  });
+});
diff --git a/tests/lib/snapshot-differ-stress.test.ts b/tests/lib/snapshot-differ-stress.test.ts
new file mode 100644
index 0000000..356fd5f
--- /dev/null
+++ b/tests/lib/snapshot-differ-stress.test.ts
@@ -0,0 +1,435 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert';
+import type { BeadIssueWithProject, BeadDependency } from '../../src/lib/types';
+import { diffSnapshots } from '../../src/lib/snapshot-differ';
+
+const MOCK_PROJECT = {
+  key: 'proj-1',
+  root: 'C:\\test',
+  displayPath: 'test',
+  name: 'Test Project',
+  source: 'local' as const,
+  addedAt: null,
+};
+
+function createMockIssue(id: string, overrides: Partial<BeadIssueWithProject> = {}): BeadIssueWithProject {
+  return {
+    id,
+    title: `Title ${id}`,
+    description: null,
+    status: 'open',
+    priority: 2,
+    issue_type: 'task',
+    assignee: null,
+    owner: 'owner',
+    labels: [],
+    dependencies: [],
+    created_at: '2026-02-13T00:00:00Z',
+    updated_at: '2026-02-13T00:00:00Z',
+    closed_at: null,
+    close_reason: null,
+    closed_by_session: null,
+    created_by: 'creator',
+    due_at: null,
+    estimated_minutes: null,
+    external_ref: null,
+    metadata: {},
+    project: MOCK_PROJECT,
+    ...overrides,
+  };
+}
+
+describe('Snapshot Differ Stress Tests', () => {
+  describe('HIGH-FREQUENCY BURSTS', () => {
+    it('should capture only final diff when status changes multiple times (simulated burst)', () => {
+      const prev = [createMockIssue('bb-1', { status: 'open' })];
+      const curr = [createMockIssue('bb-1', { status: 'closed' })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'closed');
+      assert.strictEqual(events[0].payload.from, 'open');
+      assert.strictEqual(events[0].payload.to, 'closed');
+    });
+
+    it('should handle rapid status oscillation (open -> in_progress -> blocked -> in_progress)', () => {
+      const prev = [createMockIssue('bb-1', { status: 'open' })];
+      const curr = [createMockIssue('bb-1', { status: 'in_progress' })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'status_changed');
+    });
+  });
+
+  describe('BATCH MUTATIONS', () => {
+    it('should handle 50+ beads all changing status simultaneously', () => {
+      const prev: BeadIssueWithProject[] = [];
+      const curr: BeadIssueWithProject[] = [];
+      
+      for (let i = 1; i <= 50; i++) {
+        curr.push(createMockIssue(`bb-${i}`, { status: 'open' }));
+      }
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 50);
+      events.forEach(e => {
+        assert.strictEqual(e.kind, 'created');
+      });
+    });
+
+    it('should handle 100 beads with mixed status transitions', () => {
+      const prev: BeadIssueWithProject[] = [];
+      const curr: BeadIssueWithProject[] = [];
+      
+      for (let i = 1; i <= 100; i++) {
+        if (i <= 50) {
+          prev.push(createMockIssue(`bb-${i}`, { status: 'open' }));
+          curr.push(createMockIssue(`bb-${i}`, { status: 'in_progress' }));
+        } else {
+          curr.push(createMockIssue(`bb-${i}`, { status: 'open' }));
+        }
+      }
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 100);
+      
+      const statusChanged = events.filter(e => e.kind === 'status_changed');
+      const created = events.filter(e => e.kind === 'created');
+      assert.strictEqual(statusChanged.length, 50);
+      assert.strictEqual(created.length, 50);
+    });
+  });
+
+  describe('COMPLEX PERMUTATIONS', () => {
+    it('should emit events for status + assignee + priority + labels all changing on same bead', () => {
+      const prev = [createMockIssue('bb-1', {
+        status: 'open',
+        assignee: null,
+        priority: 2,
+        labels: ['bug'],
+      })];
+      const curr = [createMockIssue('bb-1', {
+        status: 'in_progress',
+        assignee: 'alice',
+        priority: 1,
+        labels: ['bug', 'urgent'],
+      })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 4);
+      
+      const kinds = events.map(e => e.kind);
+      assert.ok(kinds.includes('status_changed'));
+      assert.ok(kinds.includes('assignee_changed'));
+      assert.ok(kinds.includes('priority_changed'));
+      assert.ok(kinds.includes('labels_changed'));
+    });
+
+    it('should handle all trackable fields changing simultaneously', () => {
+      const prev = [createMockIssue('bb-1', {
+        status: 'open',
+        title: 'Old Title',
+        description: null,
+        priority: 3,
+        issue_type: 'task',
+        assignee: null,
+        labels: [],
+        dependencies: [],
+        due_at: null,
+        estimated_minutes: null,
+      })];
+      const curr = [createMockIssue('bb-1', {
+        status: 'in_progress',
+        title: 'New Title',
+        description: 'New description',
+        priority: 1,
+        issue_type: 'feature',
+        assignee: 'bob',
+        labels: ['enhancement'],
+        dependencies: [{ type: 'blocks', target: 'bb-2' }],
+        due_at: '2026-02-20T00:00:00Z',
+        estimated_minutes: 120,
+      })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 10);
+      
+      const kinds = events.map(e => e.kind);
+      assert.ok(kinds.includes('status_changed'));
+      assert.ok(kinds.includes('title_changed'));
+      assert.ok(kinds.includes('description_changed'));
+      assert.ok(kinds.includes('priority_changed'));
+      assert.ok(kinds.includes('type_changed'));
+      assert.ok(kinds.includes('assignee_changed'));
+      assert.ok(kinds.includes('labels_changed'));
+      assert.ok(kinds.includes('dependency_added'));
+      assert.ok(kinds.includes('due_date_changed'));
+      assert.ok(kinds.includes('estimate_changed'));
+    });
+  });
+
+  describe('NULL SAFETY', () => {
+    it('should NOT crash when labels is null in prev (DOCUMENTS BUG - will throw TypeError)', () => {
+      const prev = [createMockIssue('bb-1', { labels: null as unknown as string[] })];
+      const curr = [createMockIssue('bb-1', { labels: ['bug'] })];
+      
+      assert.throws(() => {
+        diffSnapshots(prev, curr);
+      }, /TypeError|Cannot read properties of null/);
+    });
+
+    it('should NOT crash when labels is null in curr (DOCUMENTS BUG - will throw TypeError)', () => {
+      const prev = [createMockIssue('bb-1', { labels: ['bug'] })];
+      const curr = [createMockIssue('bb-1', { labels: null as unknown as string[] })];
+      
+      assert.throws(() => {
+        diffSnapshots(prev, curr);
+      }, /TypeError|Cannot read properties of null/);
+    });
+
+    it('should NOT crash when dependencies is null (DOCUMENTS BUG - will throw TypeError)', () => {
+      const prev = [createMockIssue('bb-1', { dependencies: null as unknown as BeadDependency[] })];
+      const curr = [createMockIssue('bb-1', { dependencies: [] })];
+      
+      assert.throws(() => {
+        diffSnapshots(prev, curr);
+      }, /TypeError|Cannot read properties of null/);
+    });
+
+    it('should NOT crash when dependencies is undefined in curr (DOCUMENTS BUG - will throw TypeError)', () => {
+      const prev = [createMockIssue('bb-1', { dependencies: [] })];
+      const curr = [createMockIssue('bb-1', { dependencies: undefined as unknown as BeadDependency[] })];
+      
+      assert.throws(() => {
+        diffSnapshots(prev, curr);
+      }, /TypeError|Cannot read properties of undefined/);
+    });
+  });
+
+  describe('EMPTY ARRAYS', () => {
+    it('should not emit event when labels goes from empty to empty', () => {
+      const prev = [createMockIssue('bb-1', { labels: [] })];
+      const curr = [createMockIssue('bb-1', { labels: [] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should emit labels_changed when labels goes from empty to non-empty', () => {
+      const prev = [createMockIssue('bb-1', { labels: [] })];
+      const curr = [createMockIssue('bb-1', { labels: ['bug'] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'labels_changed');
+    });
+
+    it('should emit labels_changed when labels goes from non-empty to empty', () => {
+      const prev = [createMockIssue('bb-1', { labels: ['bug'] })];
+      const curr = [createMockIssue('bb-1', { labels: [] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'labels_changed');
+    });
+
+    it('should not emit event when dependencies goes from empty to empty', () => {
+      const prev = [createMockIssue('bb-1', { dependencies: [] })];
+      const curr = [createMockIssue('bb-1', { dependencies: [] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should emit dependency_added when dependencies goes from empty to non-empty', () => {
+      const prev = [createMockIssue('bb-1', { dependencies: [] })];
+      const curr = [createMockIssue('bb-1', { dependencies: [{ type: 'blocks', target: 'bb-2' }] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'dependency_added');
+    });
+
+    it('should emit dependency_removed when dependencies goes from non-empty to empty', () => {
+      const prev = [createMockIssue('bb-1', { dependencies: [{ type: 'blocks', target: 'bb-2' }] })];
+      const curr = [createMockIssue('bb-1', { dependencies: [] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'dependency_removed');
+    });
+  });
+
+  describe('DELETION DETECTION', () => {
+    it('should NOT emit any event when issue is deleted (DOCUMENTS CURRENT BEHAVIOR - no deletion event)', () => {
+      const prev = [createMockIssue('bb-1')];
+      const curr: BeadIssueWithProject[] = [];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should NOT emit deletion event when multiple issues are removed', () => {
+      const prev = [
+        createMockIssue('bb-1'),
+        createMockIssue('bb-2'),
+        createMockIssue('bb-3'),
+      ];
+      const curr = [createMockIssue('bb-2')];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should still emit created events for new issues even when others are deleted', () => {
+      const prev = [createMockIssue('bb-1')];
+      const curr = [createMockIssue('bb-2')];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'created');
+      assert.strictEqual(events[0].beadId, 'bb-2');
+    });
+  });
+
+  describe('LABELS ORDER INDEPENDENCE', () => {
+    it('should NOT emit labels_changed when same labels are in different order', () => {
+      const prev = [createMockIssue('bb-1', { labels: ['bug', 'ui', 'urgent'] })];
+      const curr = [createMockIssue('bb-1', { labels: ['urgent', 'bug', 'ui'] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should NOT emit labels_changed for single label (trivially same order)', () => {
+      const prev = [createMockIssue('bb-1', { labels: ['bug'] })];
+      const curr = [createMockIssue('bb-1', { labels: ['bug'] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should handle large label sets with shuffled order', () => {
+      const labels = Array.from({ length: 20 }, (_, i) => `label-${i}`);
+      const shuffled = [...labels].reverse();
+      
+      const prev = [createMockIssue('bb-1', { labels })];
+      const curr = [createMockIssue('bb-1', { labels: shuffled })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+  });
+
+  describe('DUPLICATE LABELS', () => {
+    it('should NOT emit event when labels have same duplicates in same order', () => {
+      const prev = [createMockIssue('bb-1', { labels: ['bug', 'bug', 'ui'] })];
+      const curr = [createMockIssue('bb-1', { labels: ['bug', 'bug', 'ui'] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should NOT emit event when labels have same duplicates in different order', () => {
+      const prev = [createMockIssue('bb-1', { labels: ['bug', 'bug', 'ui'] })];
+      const curr = [createMockIssue('bb-1', { labels: ['ui', 'bug', 'bug'] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should emit event when duplicate count differs', () => {
+      const prev = [createMockIssue('bb-1', { labels: ['bug', 'bug'] })];
+      const curr = [createMockIssue('bb-1', { labels: ['bug'] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'labels_changed');
+    });
+
+    it('should emit event when new duplicate is added', () => {
+      const prev = [createMockIssue('bb-1', { labels: ['bug'] })];
+      const curr = [createMockIssue('bb-1', { labels: ['bug', 'bug'] })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      assert.strictEqual(events[0].kind, 'labels_changed');
+    });
+  });
+
+  describe('EDGE CASES', () => {
+    it('should handle null previous snapshot (first load)', () => {
+      const curr = [createMockIssue('bb-1'), createMockIssue('bb-2')];
+      
+      const events = diffSnapshots(null, curr);
+      assert.strictEqual(events.length, 2);
+      events.forEach(e => {
+        assert.strictEqual(e.kind, 'created');
+      });
+    });
+
+    it('should handle empty previous and current snapshots', () => {
+      const events = diffSnapshots([], []);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should handle same issue in both snapshots with no changes', () => {
+      const issue = createMockIssue('bb-1');
+      const events = diffSnapshots([issue], [issue]);
+      assert.strictEqual(events.length, 0);
+    });
+
+    it('should handle multiple dependency changes on same bead', () => {
+      const prev = [createMockIssue('bb-1', {
+        dependencies: [
+          { type: 'blocks', target: 'bb-2' },
+          { type: 'relates_to', target: 'bb-3' },
+        ],
+      })];
+      const curr = [createMockIssue('bb-1', {
+        dependencies: [
+          { type: 'blocks', target: 'bb-4' },
+        ],
+      })];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 3);
+      
+      const kinds = events.map(e => e.kind);
+      assert.ok(kinds.includes('dependency_added'));
+      assert.ok(kinds.filter(k => k === 'dependency_removed').length === 2);
+    });
+
+    it('should generate valid UUIDs for all events', () => {
+      const prev: BeadIssueWithProject[] = [];
+      const curr = [createMockIssue('bb-1')];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events.length, 1);
+      
+      const uuidRegex = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+      assert.match(events[0].id, uuidRegex);
+    });
+
+    it('should include correct project info in events', () => {
+      const prev: BeadIssueWithProject[] = [];
+      const curr = [createMockIssue('bb-1')];
+      
+      const events = diffSnapshots(prev, curr);
+      assert.strictEqual(events[0].projectId, 'proj-1');
+      assert.strictEqual(events[0].projectName, 'Test Project');
+    });
+
+    it('should compute actor from assignee or owner or created_by', () => {
+      const events1 = diffSnapshots([], [createMockIssue('bb-1', { assignee: 'alice', owner: 'bob', created_by: 'charlie' })]);
+      assert.strictEqual(events1[0].actor, 'alice');
+
+      const events2 = diffSnapshots([], [createMockIssue('bb-1', { assignee: null, owner: 'bob', created_by: 'charlie' })]);
+      assert.strictEqual(events2[0].actor, 'bob');
+
+      const events3 = diffSnapshots([], [createMockIssue('bb-1', { assignee: null, owner: null, created_by: 'charlie' })]);
+      assert.strictEqual(events3[0].actor, 'charlie');
+    });
+  });
+});
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