fix: improve lib_symbols name matching for pin location

get_symbol_pins() matching now uses 4 strategies in priority order:
1. Exact full lib_id match (unchanged)
2. Bare name exact match (strip library prefix from both sides)
3. Bare name prefix match with unit suffix _N (unchanged)
4. NEW: Substring match — lib_id bare name appears inside symbol_name

This fixes 'pins not locatable' errors for symbols like
Regulator_Linear:AMS1117-3.3 and Device:C where the lib_symbols
entry uses a name format that differs from the instance lib_id.

Also improved: when no match is found, logs available symbol names
for debugging.

Bug: connect_to_net/batch_connect fail to locate pins for some symbols
Ref: agentmemory ID 919adb50 (2026-06-22)

python/commands/pin_locator.py

@@ -143,7 +143,14 @@ class PinLocator:
             # KiCad lib_symbols may use a different name than the instance lib_id:
             #   instance lib_id:  "stat-tis-custom:BAT_18650"
             #   lib_symbols name: "BAT_18650_3"  (prefix stripped, unit suffix added)
-            # Strategy: exact match first, then bare-name prefix match.
+            #   instance lib_id:  "Regulator_Linear:AMS1117-3.3"
+            #   lib_symbols name: "AMS1117-3.3_0_1"  (multi-unit symbol)
+            #
+            # Strategy (in priority order):
+            #   1. Exact match on full lib_id
+            #   2. Bare name exact match (strip library prefix from both sides)
+            #   3. Bare name prefix match with unit suffix (_N)
+            #   4. Substring match (lib_id bare name appears inside symbol_name)
             bare_name = lib_id.split(":")[-1] if ":" in lib_id else lib_id
 
             best_match = None
@@ -151,18 +158,31 @@ class PinLocator:
                 if not (isinstance(item, list) and len(item) > 1 and item[0] == Symbol("symbol")):
                     continue
                 symbol_name = str(item[1]).strip('"')
+                sn_bare = symbol_name.split(":")[-1] if ":" in symbol_name else symbol_name
+
+                # Strategy 1: Exact full lib_id match
                 if symbol_name == lib_id:
                     best_match = item
                     break
-                if best_match is None:
-                    sn_bare = symbol_name.split(":")[-1] if ":" in symbol_name else symbol_name
-                    if sn_bare == bare_name or (
-                        sn_bare.startswith(bare_name)
-                        and len(sn_bare) > len(bare_name)
-                        and sn_bare[len(bare_name)] == "_"
-                        and sn_bare[len(bare_name) + 1 :].isdigit()
-                    ):
-                        best_match = item
+
+                # Strategy 2: Bare name exact match
+                if best_match is None and sn_bare == bare_name:
+                    best_match = item
+
+                # Strategy 3: Bare name prefix match with unit suffix (_N)
+                if best_match is None and (
+                    sn_bare.startswith(bare_name)
+                    and len(sn_bare) > len(bare_name)
+                    and sn_bare[len(bare_name)] == "_"
+                    and sn_bare[len(bare_name) + 1 :].isdigit()
+                ):
+                    best_match = item
+
+                # Strategy 4: Substring match — lib_id bare name appears inside symbol_name
+                # (handles cases like "AMS1117-3.3" matching "AMS1117-3.3_0_1" or
+                #  names with extra KiCad-generated suffixes beyond unit numbers)
+                if best_match is None and bare_name in sn_bare:
+                    best_match = item
 
             if best_match is not None:
                 matched_name = str(best_match[1]).strip('"')
@@ -176,8 +196,17 @@ class PinLocator:
                     logger.info(f"Extracted {len(pins)} pins from {lib_id}")
                 return pins
 
-            logger.warning(f"Symbol {lib_id} not found in lib_symbols")
-            return {}
+            # When no match is found, list available symbol names for debugging
+            if best_match is None:
+                available = []
+                for item in lib_symbols[1:]:
+                    if isinstance(item, list) and len(item) > 1 and item[0] == Symbol("symbol"):
+                        available.append(str(item[1]).strip('"'))
+                logger.warning(
+                    f"Symbol {lib_id} (bare: '{bare_name}') not found in lib_symbols. "
+                    f"Available ({len(available)}): {available[:10]}{'...' if len(available) > 10 else ''}"
+                )
+                return {}
 
         except Exception as e:
             logger.error(f"Error getting symbol pins: {e}")