fix(test): remove seal suffixes from institution names before matching

Extend institution name cleaning to handle OCR artifacts from seal text
that gets merged with company names during extraction.

Problem:
- 3 PDFs failed matching due to "检验检测专用章" (Seal for Inspection & Testing)
  being included in extracted institution names
- Example: "四川合泰与必摩适检测有限公司检验检测专用章"
           vs "四川合泰与必摩适检测有限公司"
- Similarity dropped to ~60-67% → incorrectly classified as "no_match"
- Affected PDFs:
  * pages3-6.pdf: 60.87% similarity
  * pages7-14.pdf: 60.0% similarity
  * pages12-15.pdf: 62.5% similarity

Solution:
- Add seal suffix removal to clean_institution_name() function
- Remove common seal names: 检验检测专用章, 检测专用章, 检验专用章, etc.
- Use string replacement (not regex) to handle middle-of-text occurrences
- Apply before number removal to handle combined artifacts like "专用章123456"

Test Results:
All 4 test cases now achieve 100% similarity and "exact" match:
1. "检验检测专用章" suffix → 66.67% → 100.00% ✓
2. "检验检测专用章" suffix (different company) → 65.00% → 100.00% ✓
3. "430334" suffix → 70.00% → 100.00% ✓
4. "检验检测专用章430334" combined → 51.85% → 100.00% ✓

This fix complements the previous CMA code suffix removal and
significantly improves matching accuracy for seal-related OCR artifacts.

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

test_accuracy_batch_full.py

@@ -1511,7 +1511,7 @@ def extract_institution_from_crt(pdf_path: str) -> List[str]:
 
 def clean_institution_name(text: str) -> str:
     """
-    清理机构名称，移除末尾的数字、CMA码等干扰内容
+    清理机构名称，移除末尾的数字、CMA码、印章名称等干扰内容
 
     Args:
         text: 原始机构名称
@@ -1522,6 +1522,19 @@ def clean_institution_name(text: str) -> str:
     if not text:
         return text
 
+    # 移除常见的印章名称（不需要在末尾，可以移除任何位置的）
+    # 这处理"机构名称检验检测专用章"或"机构名称检验检测专用章123456"
+    seal_patterns = [
+        r'检验检测专用章',
+        r'检测专用章',
+        r'检验专用章',
+        r'鉴定专用章',
+        r'公章',
+        r'专用章',
+    ]
+    for pattern in seal_patterns:
+        text = text.replace(pattern, '')
+
     # 移除末尾的数字序列（如CMA码）
     text = re.sub(r'\d{6,}$', '', text)  # 6位及以上数字
     text = re.sub(r'\d{11,}$', '', text)  # 11位及以上数字（CMA码）