Implement Phase 5: Product Owner Dashboard (User Story 3)

Add complete dashboard functionality for product owners and administrators to view, filter, search, and manage feedback submissions following Test-First Discipline.

Tests (T093-T105):
- Add 12 contract tests for dashboard routes (authentication, listing, filtering, search, detail view, status updates, attachment downloads, access control)
- Add 2 integration tests for complete dashboard workflow and access control enforcement
- All tests written first and verified to fail before implementation

Services (T111-T118):
- Enhance FeedbackStorageService with load_feedback_list() for pagination, filtering, searching, and sorting
- Add load_feedback_detail() to load complete feedback with attachments and analysis
- Add update_feedback_status_by_id() for status management
- Add get_attachment_path() with path traversal prevention

Routes (T119-T134):
- Implement GET /dashboard with filters, search, and pagination (50 items/page)
- Implement GET /feedback/<id> detail view with role-based access control
- Implement POST /feedback/<id>/status for status updates
- Implement GET /feedback/<id>/attachment/<filename> for secure file downloads
- Add access control helpers (administrators see all products, owners see only assigned)

Templates (T135-T136):
- Create dashboard/list.html with filter form, search, and pagination
- Create dashboard/detail.html with status update form and attachment links
- Create error_403.html for access denied
- Create error_404.html for not found

Integration & Bug Fixes:
- Update auth routes to remove /auth prefix and redirect to dashboard after login
- Update Feedback.VALID_STATUSES to include dashboard statuses (in_progress, resolved, closed)
- Register error handlers for 403 and 404 in app factory
- Fix test fixtures to use correct users.yaml format and User.hash_password()

Test Results: 39 passed, 1 skipped (all Phase 5 tests passing)

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

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

app/__init__.py

@@ -70,4 +70,17 @@ def create_app(config_name='development'):
         from flask import render_template
         return render_template('index.html')
 
+    # Register error handlers
+    @app.errorhandler(403)
+    def forbidden(e):
+        """Handle 403 Forbidden errors"""
+        from flask import render_template
+        return render_template('error_403.html'), 403
+
+    @app.errorhandler(404)
+    def not_found(e):
+        """Handle 404 Not Found errors"""
+        from flask import render_template
+        return render_template('error_404.html'), 404
+
     return app