Initial commit: CMM Report Analyzer

FastAPI app that parses CMM inspection reports (PDF/Excel/CSV),
computes SPC metrics (Cp/Cpk/Pp/Ppk, control limits, Shapiro-Wilk),
generates interactive Plotly charts, and provides AI-powered quality
summaries via Azure OpenAI with graceful fallback.

Includes 21 passing tests covering parsers, SPC calculations, and
API endpoints.

tests/test_spc.py

@@ -0,0 +1,84 @@
+from app.analysis.spc import SPCResult, calculate_spc
+from app.parsers.models import MeasurementRecord
+
+
+def _make_records(name: str, nominal: float, tol: float, actuals: list[float]):
+    return [
+        MeasurementRecord(
+            feature_name=name,
+            nominal=nominal,
+            tolerance_plus=tol,
+            tolerance_minus=-tol,
+            actual=a,
+            deviation=a - nominal,
+        )
+        for a in actuals
+    ]
+
+
+def test_single_measurement_returns_none_indices():
+    records = _make_records("D1", 10.0, 0.05, [10.01])
+    results = calculate_spc(records)
+    assert len(results) == 1
+    r = results[0]
+    assert r.cp is None
+    assert r.cpk is None
+    assert r.pp is None
+    assert r.ppk is None
+
+
+def test_basic_spc_calculation():
+    actuals = [10.01, 10.02, 9.99, 10.00, 10.03, 9.98, 10.01, 10.02, 9.99, 10.00]
+    records = _make_records("D1", 10.0, 0.05, actuals)
+    results = calculate_spc(records)
+
+    assert len(results) == 1
+    r = results[0]
+    assert r.n == 10
+    assert r.pp is not None
+    assert r.ppk is not None
+    assert r.cp is not None
+    assert r.cpk is not None
+    assert r.pp > 0
+    assert r.cpk > 0
+    assert r.out_of_spec_count == 0
+
+
+def test_out_of_spec_count():
+    actuals = [10.0, 10.06, 9.94, 10.0, 10.0]  # 10.06 and 9.94 outside ±0.05
+    records = _make_records("D1", 10.0, 0.05, actuals)
+    results = calculate_spc(records)
+    assert results[0].out_of_spec_count == 2
+
+
+def test_multiple_features():
+    records = (
+        _make_records("D1", 10.0, 0.05, [10.01, 10.02, 9.99])
+        + _make_records("D2", 20.0, 0.10, [20.05, 19.95, 20.01])
+    )
+    results = calculate_spc(records)
+    assert len(results) == 2
+    names = {r.feature_name for r in results}
+    assert names == {"D1", "D2"}
+
+
+def test_shapiro_not_computed_for_small_n():
+    records = _make_records("D1", 10.0, 0.05, [10.01, 10.02])
+    results = calculate_spc(records)
+    assert results[0].shapiro_p is None
+
+
+def test_shapiro_computed_for_n_ge_3():
+    records = _make_records("D1", 10.0, 0.05, [10.01, 10.02, 9.99])
+    results = calculate_spc(records)
+    assert results[0].shapiro_p is not None
+
+
+def test_to_dict():
+    records = _make_records("D1", 10.0, 0.05, [10.01, 10.02, 9.99, 10.00, 10.03])
+    results = calculate_spc(records)
+    d = results[0].to_dict()
+    assert "feature_name" in d
+    assert "cpk" in d
+    assert "values" in d
+    assert isinstance(d["values"], list)