Implement Phase 4: AI-Powered Feedback Analysis (User Story 2)

Implement automatic AI analysis of feedback submissions using Claude API,
including language detection, categorization, summarization, and translation
to product owner's preferred language.

Tasks Completed (T065-T092):
- T065-T069: Unit tests for AI analyzer (5 tests)
- T070: Integration test for full AI analysis workflow
- T071: Created AIAnalyzer abstract base class interface
- T072: Added AnalysisResult dataclass to feedback model
- T073: Implemented ClaudeAnalyzer with Anthropic SDK
- T074: Integrated Claude API with 45s timeout
- T075: Designed single-call analysis prompt
- T076: Language detection implementation
- T077: Category extraction with validation
- T078: Summary generation (1-2 sentences)
- T079: Translation extraction
- T080: Timeout handling for Claude API
- T081: API error handling with proper exceptions
- T082: Analysis storage to analysis.md file
- T083: Formatted markdown output for analysis
- T084: Background analysis trigger on submission
- T085: Non-blocking async analysis via threading
- T086: Status update to 'analyzing' before analysis
- T087: Status update to 'analyzed' on success
- T088: Status update to 'analysis_failed' on error
- T089: Metadata update with category and language
- T090: Environment configuration for ANTHROPIC_API_KEY
- T091: Verification that original content.txt preserved (FR-016)
- T092: Verification that images not analyzed via OCR (FR-021)

Features:
- Abstract AIAnalyzer interface for multiple AI providers
- ClaudeAnalyzer implementation using Anthropic API
- Background threading for non-blocking analysis
- Flask app context management in background threads
- Comprehensive error handling and status tracking
- Original content preservation (FR-016 compliance)
- Image storage without OCR (FR-021 compliance)

Testing:
- 5 unit tests for AI analyzer components
- 2 integration tests for full analysis workflow
- All 46 tests passing (1 skipped)
- Mock-based testing to avoid API calls

Files Changed:
- app/models/feedback.py: Added AnalysisResult dataclass
- app/routes/submission.py: Background analysis integration
- app/services/ai_analyzer.py: NEW - AI analysis service
- app/services/feedback_storage.py: Analysis storage methods
- tests/unit/test_ai_analyzer.py: NEW - Unit tests (5 tests)
- tests/integration/test_ai_analysis_flow.py: NEW - Integration tests (2 tests)
- tests/integration/test_feedback_submission_flow.py: Threading mock added

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

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

app/models/feedback.py

@@ -2,6 +2,7 @@
 import os
 import uuid
 from datetime import datetime
+from dataclasses import dataclass
 import yaml
 from flask import current_app
 
@@ -254,3 +255,21 @@ class Feedback:
             bool: True if status is valid, False otherwise
         """
         return self.status in self.VALID_STATUSES
+
+
+@dataclass
+class AnalysisResult:
+    """Result of AI-powered feedback analysis
+
+    Attributes:
+        category: Feedback category (bug, feature_request, question, complaint, praise, other)
+        original_language: Detected language code (e.g., 'en', 'de', 'fr')
+        summary: Brief summary of feedback (1-2 sentences)
+        translation: Feedback translated to target language
+        raw_analysis: Full analysis text in markdown format
+    """
+    category: str
+    original_language: str
+    summary: str
+    translation: str
+    raw_analysis: str