feat: Phase 2 complete — 13 Phases of COBOL type classification and test benchmark

P0.6: gcov infrastructure
P1: extract_structure output expansion (11 new feature fields)
P2: Confusion group rule engine (8 pairs + contradiction + backtrack)
P3: 4-factor confidence calculation + quality gate update
P4: 33+2 COBOL program type test samples (22 files, 7 categories)
P5: parametrized/ test data generation engine
P6: japanese_data.py lookup tables
P7-10: Type-specific test suites (~159 parametrized tests)
P11: Full classification pipeline (classify_program) + orchestrator integration
P12: Documentation (module-interfaces, test-plan v3.0, coverage-matrix)

Architecture decisions:
- classification_pipeline/ merged to hina/pipeline/
- parametrized/ as independent module
- japanese_data.py as root-level file
- hina/__all__ only exports classify_program()

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

tests/test_preprocessor.py

@@ -0,0 +1,31 @@
+"""PP-01~03: CopybookPreprocessor"""
+
+import sys, os, tempfile
+from pathlib import Path
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
+from preprocessor import CopybookPreprocessor
+
+
+def test_expand_found():
+    """PP-01: COPY 文件存在时展开"""
+    with tempfile.TemporaryDirectory() as tmp:
+        cpy = Path(tmp) / "MYCPY.cpy"
+        cpy.write_text("01 WS-FIELD PIC 9.")
+        p = CopybookPreprocessor(paths=[tmp])
+        text = p.expand("       COPY MYCPY.\n")
+        assert "WS-FIELD" in text
+
+
+def test_expand_not_found():
+    """PP-02: COPY 不存在 → NOT FOUND"""
+    with tempfile.TemporaryDirectory() as tmp:
+        p = CopybookPreprocessor(paths=[tmp])
+        text = p.expand("       COPY NOTEXIST.\n")
+        assert "NOT FOUND" in text
+
+
+def test_expand_no_copy():
+    """PP-03: 无 COPY → 原文"""
+    p = CopybookPreprocessor()
+    text = p.expand("       MOVE 1 TO A.\n")
+    assert "MOVE 1 TO A" in text