bipeds.h: biped_approximate_surface_index returns long (ai_script: 1 function strict exact)

Header packet P4 (150K lane). January's only external caller, ai_script.obj, tests the result with a full 32-bit cmp eax,-1 (no sign extension); the short prototype produced cmp ax,0xffff. The owner prototype and the bipeds.c definition now return long and the unevidenced (short) cast is dropped; declaration count unchanged, callee bytes unchanged. _ai_scripting_teleport_starting_location_private (288) becomes strict exact with an untouched body, so its park (premise: the widening perturbs consumers) is removed.

Consumers: 23 bipeds.h includers, shadow-compiled H vs P (0 losses). Live tree: full ninja + stable_verdicts sweep +1 gained / 0 regressions; parks 290/0/0.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

config/parked.json

@@ -4725,17 +4725,6 @@
         "objdiff_percent": 81.60833
       }
     },
-    {
-      "unit": "source/ai/ai_script",
-      "function": "_ai_scripting_teleport_starting_location_private",
-      "class": "instruction-scheduling",
-      "evidence": "Complete typed HCEA-backed teleport helper retained under its authenticated semantic private name. Target and candidate both occupy 288 padded bytes and have the same 13 relocation destinations; the remaining one-byte schedule displacement begins after the January biped_approximate_surface_index call. Widening that shared function's return type can close this helper but perturbs accepted consumers, so that ABI change is rejected. This natural body receives zero credit. See docs/object_matching_logs/ai_flee_teleport_model_node_packet_20260912.md.",
-      "measurements": {
-        "target": { "size": 288, "relocation_count": 13, "normalized_sha256": "755b7a6e2990f977b15fb61eb09a0106990c68fcd7d69128922e69cc12e52c5e" },
-        "base": { "size": 288, "relocation_count": 13, "normalized_sha256": "9c0415c2243227d13b1b96ca944e476f75acf40417113dab2fc3edcaa501b22e" },
-        "objdiff_percent": 99.9375
-      }
-    },
     {
       "unit": "source/items/weapons",
       "function": "_weapon_can_be_fired",

source/units/bipeds.c

@@ -1492,11 +1492,11 @@ static long biped_find_ground_surface(
 	return surface_index;
 }
 
-short biped_approximate_surface_index(
+long biped_approximate_surface_index(
 	long biped_index,
 	real_point3d *point)
 {
-	return (short)biped_find_ground_surface(biped_index, global_down3d, 2.f, point, NULL);
+	return biped_find_ground_surface(biped_index, global_down3d, 2.f, point, NULL);
 }
 
 long biped_find_pathfinding_surface_index(

source/units/bipeds.h

@@ -158,7 +158,7 @@ void biped_falling_danger(
 	long biped_index);
 void biped_render_debug(
 	long biped_index);
-short biped_approximate_surface_index(
+long biped_approximate_surface_index(
 	long biped_index,
 	real_point3d *point);
 long biped_find_pathfinding_surface_index(