fix(pin_locator): rstrip "_" in WireDragger.find_symbol; clean stale tests

Resolves the four failing tests in tests/test_pin_locator_and_component.py
left behind by the PR #145 / commit 3c22580 Y-flip work.

Per-test rationale:

- TestPinLocatorYAxisNegation::{test_pin1_y_above_center_for_rotation_0,
  test_pin2_y_below_center_for_rotation_0, test_pin1_rotated_90}: stale.
  Their assertions encoded the *correct* post-PR-145 convention (96.19,
  103.81, etc.), but their setup MagicMock'd self._schematic_cache while
  bypassing _get_symbol_transform, which reads the .kicad_sch file
  directly via sexpdata. The end-to-end Y-flip behaviour is already
  covered against eeschema in tests/test_pin_locator_y_flip.py — keeping
  three mock-based duplicates added no value, so they were removed.

- TestPinLocatorReferenceRstrip::test_get_pin_location_finds_symbol_with_trailing_underscore:
  revealed a real production bug. PinLocator.get_pin_location strips a
  trailing "_" on the kicad-skip lookup path, but the sexpdata-based
  _get_symbol_transform delegates to WireDragger.find_symbol which used an
  exact-equality comparison. With kicad-skip's "R1_" artifact the function
  returned None, so the whole pin-location call failed even when the symbol
  was clearly present. Fixed find_symbol to apply the same rstrip("_") on
  the stored reference before comparing, mirroring the existing behaviour
  in PinLocator. The test was also rewritten to use a real temp .kicad_sch
  (with the on-disk reference mangled to "R1_") so it actually exercises
  both lookup paths instead of bypassing one with mocks.

Files changed:
- python/commands/wire_dragger.py:78-89 — rstrip("_") on the reference
  read out of the symbol property before comparing to the caller-supplied
  reference.
- tests/test_pin_locator_and_component.py — removed three stale mock-based
  Y-axis tests (covered by tests/test_pin_locator_y_flip.py end-to-end);
  rewrote rstrip tests to use a real schematic file so _get_symbol_transform
  is actually exercised.

Verified: tests/test_pin_locator_and_component.py + test_pin_locator_y_flip.py
+ test_get_pin_angle.py + test_move_with_wire_preservation.py — 69 passed.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

python/commands/wire_dragger.py

@@ -75,14 +75,17 @@ class WireDragger:
             if not (isinstance(item, list) and item and item[0] == sym_k):
                 continue
 
-            # Check Reference property
+            # Check Reference property.
+            # kicad-skip may write a trailing "_" on references (e.g. "R1_") when
+            # cloning symbols; strip it so callers passing the canonical "R1"
+            # still find the symbol. Mirrors the rstrip in PinLocator.get_pin_location.
             ref_val = None
             for sub in item[1:]:
                 if isinstance(sub, list) and len(sub) >= 3 and sub[0] == prop_k:
                     if str(sub[1]).strip('"') == "Reference":
                         ref_val = str(sub[2]).strip('"')
                         break
-            if ref_val != reference:
+            if ref_val is None or ref_val.rstrip("_") != reference:
                 continue
 
             old_x = old_y = rotation = 0.0