Reuse datasheet family aliases and skip the LLM for catalog passives.

Store BOM MPN and orderable code on the same PDF blob, derive TI datasheet slugs from package/Q1 codes, and map LCSC/DigiKey R/C/L parameters to specs without a model call.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_passive_from_distributor.py

@@ -0,0 +1,42 @@
+from backend.services.passive_from_distributor import specs_from_distributor
+
+
+def test_lcsc_description_capacitor():
+    model = specs_from_distributor(
+        mpn="CL21B225KPFNNNE",
+        params=[{"name": "Package / Case", "value": "0805"}],
+        category="Capacitors / Ceramic Capacitors",
+        description="2.2uF ±10% 10V X7R 0805",
+    )
+    assert model is not None
+    specs = model.specs
+    assert specs.component_subtype == "passive.capacitor.ceramic"
+    assert abs(specs.value_farads - 2.2e-6) < 1e-12
+    assert specs.dielectric == "X7R"
+    assert specs.package == "0805"
+
+
+def test_digikey_params_resistor():
+    model = specs_from_distributor(
+        mpn="RC0805FR-0710KL",
+        params=[
+            {"name": "Resistance", "value": "10 kOhms"},
+            {"name": "Tolerance", "value": "±1%"},
+            {"name": "Power (Watts)", "value": "0.125W"},
+            {"name": "Package / Case", "value": "0805 (2012 Metric)"},
+        ],
+        category="Resistors / Chip Resistor - Surface Mount",
+        description="RES SMD 10K OHM 1% 1/8W 0805",
+    )
+    assert model is not None
+    assert model.specs.value_ohms == 10000
+    assert model.specs.package == "0805"
+
+
+def test_skips_when_no_value():
+    assert specs_from_distributor(
+        mpn="MYSTERY",
+        params=[{"name": "Manufacturer", "value": "Murata"}],
+        category="",
+        description="some module",
+    ) is None