Add manual AI analysis trigger for existing feedback

Implement dashboard functionality to manually trigger AI analysis for
feedback that was submitted before Phase 4 or failed analysis. Adds
detection mechanism to identify which feedback has been analyzed.

Features:
- Manual analysis trigger route: POST /feedback/{id}/analyze
- Detection of whether feedback has been analyzed (analysis.md exists)
- Dashboard UI button showing "Analyze" or "Re-analyze"
- Visual feedback for feedback without text content
- Comprehensive error handling and flash messages

Implementation:
- app/routes/dashboard.py: Added trigger_analysis() route handler
- app/routes/dashboard.py: Updated detail() to pass analysis status
- app/services/feedback_storage.py: Added has_analysis() helper method
- app/templates/dashboard/detail.html: Added analyze button UI
- tests/contract/test_dashboard_routes.py: Added 3 new contract tests

Testing:
- test_post_trigger_analysis_success: Successful manual analysis
- test_post_trigger_analysis_no_content: Reject empty content
- test_post_trigger_analysis_unauthenticated: Auth required
- All 49 tests passing (1 skipped)

User Experience:
- Green box with "Analyze" button for unanalyzed feedback
- Blue box with "Re-analyze" button for already analyzed feedback
- Red box with info message for feedback without text content
- Flash messages show success/error after analysis

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/contract/test_dashboard_routes.py

@@ -3,6 +3,7 @@ import pytest
 import os
 import yaml
 import io
+from unittest.mock import Mock, patch
 from app.models.user import User
 
 
@@ -322,3 +323,114 @@ def test_access_control_owner_products(client, app, test_users, test_product):
     # Should NOT have access to feedback from test-product
     response = client.get(f'/feedback/{feedback_id}')
     assert response.status_code == 403  # Forbidden
+
+
+@pytest.mark.contract
+def test_post_trigger_analysis_success(client, app, test_users, test_product):
+    """Contract test for POST /feedback/{id}/analyze - manual analysis trigger
+
+    Expected: 302 redirect with success message, status updated to 'analyzed'
+    """
+    # Login first
+    client.post('/login', data={'username': 'admin', 'password': 'admin123'})
+
+    feedback_id = test_product['feedback_id']
+
+    # Mock the Claude API response
+    mock_api_response = Mock()
+    mock_api_response.content = [Mock(text="""
+# Feedback Analysis
+
+**Category**: bug
+
+**Original Language**: en
+
+**Summary**: User reports a test feedback issue
+
+**Translation**: (same as original)
+""")]
+
+    # Patch AI analyzer
+    with patch('app.routes.dashboard.ClaudeAnalyzer') as mock_analyzer_class:
+        mock_analyzer = Mock()
+        mock_analyzer.analyze_feedback.return_value = Mock(
+            category='bug',
+            original_language='en',
+            summary='User reports a test feedback issue',
+            translation='(same as original)',
+            raw_analysis=mock_api_response.content[0].text
+        )
+        mock_analyzer_class.return_value = mock_analyzer
+
+        with patch('app.routes.dashboard.os.getenv', return_value='test-api-key'):
+            response = client.post(f'/feedback/{feedback_id}/analyze', follow_redirects=False)
+
+    # Should redirect
+    assert response.status_code == 302
+    assert f'/feedback/{feedback_id}' in response.location
+
+    # Verify analysis was saved
+    with app.app_context():
+        data_dir = app.config['DATA_DIR']
+        analysis_file = os.path.join(
+            data_dir, 'products', 'test-product', 'feedback', feedback_id, 'analysis.md'
+        )
+        assert os.path.exists(analysis_file)
+
+
+@pytest.mark.contract
+def test_post_trigger_analysis_no_content(client, app, test_users, test_product):
+    """Contract test for POST /feedback/{id}/analyze - feedback with empty text content
+
+    Expected: 302 redirect with error message
+    """
+    # Create feedback with empty content.txt
+    with app.app_context():
+        product_dir = os.path.join(app.config['DATA_DIR'], 'products', 'test-product')
+        feedback_id = 'test-feedback-empty-text'
+        feedback_path = os.path.join(product_dir, 'feedback', feedback_id)
+        os.makedirs(feedback_path, exist_ok=True)
+
+        metadata = {
+            'feedback_id': feedback_id,
+            'product_id': 'test-product',
+            'status': 'new',
+            'submitted_at': '2025-10-16T10:00:00Z',
+            'has_attachments': True,
+            'attachment_count': 1
+        }
+
+        with open(os.path.join(feedback_path, 'metadata.yaml'), 'w') as f:
+            yaml.dump(metadata, f)
+
+        # Create empty content.txt
+        with open(os.path.join(feedback_path, 'content.txt'), 'w') as f:
+            f.write('')
+
+        # Create attachments directory to show this has attachments only
+        attachments_dir = os.path.join(feedback_path, 'attachments')
+        os.makedirs(attachments_dir, exist_ok=True)
+        with open(os.path.join(attachments_dir, 'image.png'), 'w') as f:
+            f.write('fake image data')
+
+    # Login and try to analyze
+    client.post('/login', data={'username': 'admin', 'password': 'admin123'})
+    response = client.post(f'/feedback/{feedback_id}/analyze', follow_redirects=True)
+
+    # Should show error message
+    assert response.status_code == 200
+    assert b'Cannot analyze' in response.data or b'no text content' in response.data
+
+
+@pytest.mark.contract
+def test_post_trigger_analysis_unauthenticated(client, app, test_product):
+    """Contract test for POST /feedback/{id}/analyze - unauthenticated access
+
+    Expected: 302 redirect to login
+    """
+    feedback_id = test_product['feedback_id']
+    response = client.post(f'/feedback/{feedback_id}/analyze', follow_redirects=False)
+
+    # Should redirect to login
+    assert response.status_code == 302
+    assert '/login' in response.location