feat: add multi-company batch processing

- Add CompanyAnalysisResult and BatchAnalysisResult dataclasses
- Implement analyze_companies() for concurrent batch analysis
- Implement analyze_companies_sequential() for rate-limited scenarios
- Add progress callback support for monitoring batch jobs
- Include 5 new tests for batch processing functionality
- Fix pre-existing test mock issue in test_llm.py

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

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

README.md

@@ -15,7 +15,8 @@ SPARC automatically collects, parses, and analyzes patents from companies to pro
 - **Content Minimization**: Removes verbose descriptions to reduce LLM token usage
 - **AI Analysis**: Uses Claude 3.5 Sonnet via OpenRouter to analyze innovation quality and market potential
 - **Portfolio Analysis**: Evaluates multiple patents holistically for comprehensive insights
-- **Robust Testing**: 26 tests covering all major functionality
+- **Batch Processing**: Analyze multiple companies concurrently with progress tracking
+- **Robust Testing**: 31 tests covering all major functionality
 
 ## Architecture
 
@@ -99,6 +100,33 @@ result = analyzer.analyze_single_patent(
 )
 ```
 
+### Multi-Company Batch Analysis
+
+```python
+from SPARC.analyzer import CompanyAnalyzer
+
+analyzer = CompanyAnalyzer()
+
+# Analyze multiple companies concurrently (default 3 workers)
+batch_result = analyzer.analyze_companies(
+    ["nvidia", "amd", "intel", "qualcomm"],
+    max_workers=3
+)
+
+# Access results
+print(f"Analyzed: {batch_result.total_companies}")
+print(f"Successful: {batch_result.successful}")
+print(f"Failed: {batch_result.failed}")
+
+for result in batch_result.results:
+    if result.success:
+        print(f"{result.company_name}: {result.patent_count} patents")
+        print(result.analysis)
+
+# Or use sequential processing (safer for rate limits)
+batch_result = analyzer.analyze_companies_sequential(["nvidia", "amd"])
+```
+
 ## Running Tests
 
 ```bash
@@ -130,7 +158,7 @@ pytest tests/ --cov=SPARC --cov-report=term-missing
 - [X] Extract and minimize patent content
 - [X] LLM integration for analysis
 - [X] Company performance estimation
-- [ ] Multi-company batch processing
+- [X] Multi-company batch processing
 - [ ] FastAPI web service wrapper
 - [X] Docker containerization
 - [X] Results persistence (database)