AI: use server relationships to classify NPC friendliness

- Read the server NPC's m_Relationship CUtlVector (entity row for the local
  player first, then the CLASS_PLAYER row): D_LI friendly, D_NU neutral,
  D_HT/D_FR hostile.
- Use it for ESP colours and aimbot/silent-aim/melee target filtering, with
  the existing model heuristic as a fallback.
- Treat bugbait-controlled antlions as friendly when their server
  m_hFollowTarget is set.
- Resolve m_Relationship/m_hFollowTarget datamap offsets and log them.

3 files changed, 101 insertions, 10 deletions

diff --git a/src/esp.cpp b/src/esp.cpp
index 7c3f1bc..0966ff5 100644
--- a/src/esp.cpp
+++ b/src/esp.cpp
@@ -148,6 +148,34 @@ static bool model_is_neutral(const char *m) {
   return false;
 }
 
+static bool npc_is_friendly(int idx, const char *model, int local_idx,
+                            bool &neutral) {
+  int rel = server_npc_relation(idx, local_idx);
+  if (rel == 3) { // D_LI
+    neutral = false;
+    return true;
+  }
+  if (rel == 4) { // D_NU
+    neutral = true;
+    return false;
+  }
+  if (rel == 1 || rel == 2) { // D_HT / D_FR
+    neutral = false;
+    return false;
+  }
+  // Bugbait-controlled antlions follow a target even when their default
+  // relationship was never rewritten.
+  if (model && strstr(model, "antlion") &&
+      server_npc_has_follow_target(idx)) {
+    neutral = false;
+    return true;
+  }
+  bool friendly = model_is_friendly(model);
+  neutral = model_is_neutral(model);
+  return friendly;
+}
+
+
 static void short_name(const char *model, char *out, size_t outn) {
   if (!model) { snprintf(out, outn, "NPC"); return; }
   const char *base = strrchr(model, '/');
@@ -259,8 +287,9 @@ static void esp_collect(int local_idx) {
     t.health = hp > 0 ? (float)hp : 0.0f;
     t.maxhealth = maxhp > 0 ? (float)maxhp : 100.0f;
     t.show_health = hp > 0;
-    t.friendly = model_is_friendly(model);
-    t.neutral = model_is_neutral(model);
+    bool neutral = false;
+    t.friendly = npc_is_friendly(idx, model, local_idx, neutral);
+    t.neutral = neutral;
     short_name(model, t.name, sizeof(t.name));
     if (npc && !model) snprintf(t.name, sizeof(t.name), "NPC");
   }
@@ -527,7 +556,8 @@ static bool select_aim_target(const QAngle &view, unsigned bone_mask,
     if (life != LIFE_ALIVE)
       return false;
     const char *model = entity_model_name(ent);
-    if (model_is_friendly(model) || model_is_neutral(model))
+    bool neutral = false;
+    if (npc_is_friendly(idx, model, local, neutral) || neutral)
       return false;
     if (!bones_update(idx, ent))
       return false;
@@ -605,7 +635,8 @@ static bool select_aim_target(const QAngle &view, unsigned bone_mask,
     if (life != LIFE_ALIVE)
       continue;
     const char *model = entity_model_name(ent);
-    if (model_is_friendly(model) || model_is_neutral(model))
+    bool neutral = false;
+    if (npc_is_friendly(idx, model, local, neutral) || neutral)
       continue;
 
     float maxz = g_net.maxs >= 0 ? *(float *)(e + g_net.maxs + 8) : 72.0f;
@@ -990,7 +1021,8 @@ bool melee_aimbot_apply(CUserCmd *cmd) {
     if (life != LIFE_ALIVE)
       continue;
     const char *model = entity_model_name(ent);
-    if (model_is_friendly(model) || model_is_neutral(model))
+    bool neutral = false;
+    if (npc_is_friendly(idx, model, local, neutral) || neutral)
       continue;
 
     Vector origin{*(float *)(e + g_net.origin),
@@ -1320,7 +1352,8 @@ bool triggerbot_apply(CUserCmd *cmd) {
     if (life != LIFE_ALIVE)
       return false;
     const char *model = entity_model_name(hit);
-    if (model_is_friendly(model) || model_is_neutral(model))
+    bool neutral = false;
+    if (npc_is_friendly(idx, model, local, neutral) || neutral)
       return false;
     cmd->buttons |= IN_ATTACK;
     static int logs = 0;
diff --git a/src/hl2h.h b/src/hl2h.h
index e441167..414e061 100644
--- a/src/hl2h.h
+++ b/src/hl2h.h
@@ -252,6 +252,8 @@ bool resolve_server_netvars();
 int server_entity_health(int idx, int *maxhealth, int *lifestate, void **base_out);
 bool server_set_velocity_z(int idx, float vz);
 int server_active_weapon(int idx);
+int server_npc_relation(int idx, int local_idx);
+bool server_npc_has_follow_target(int idx);
 int server_model_index(void *base);
 void find_modules();
 void init_conmsg();
diff --git a/src/server.cpp b/src/server.cpp
index 5599227..4702c44 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -25,7 +25,12 @@ enum { EDICT_UNKNOWN_OFF = 0x0C };
 
 // typedescription_t (32-bit): fieldType@0, fieldName@4, fieldOffset[0]@8,
 // fieldOffset[1]@0xC, fieldSize@0x10, flags@0x12, externalName@0x14
-enum { FIELD_INTEGER = 5, FIELD_CHARACTER = 8 };
+enum {
+  FIELD_INTEGER = 5,
+  FIELD_CHARACTER = 8,
+  FIELD_EMBEDDED = 10,
+  FIELD_EHANDLE = 13
+};
 
 int g_srv_health = -1;
 int g_srv_maxhealth = -1;
@@ -34,6 +39,8 @@ int g_srv_modelindex = -1;
 int g_srv_absvelocity = -1;
 int g_srv_velocity = -1;
 int g_srv_activeweapon = -1;
+static int g_srv_relationship = -1;
+static int g_srv_followtarget = -1;
 static bool g_srv_ready = false;
 static bool g_srv_checked = false;
 
@@ -110,14 +117,17 @@ bool resolve_server_netvars() {
   g_srv_modelindex = datamap_offset("m_nModelIndex", 7); // FIELD_SHORT
   g_srv_absvelocity = datamap_offset("m_vecAbsVelocity", 3); // FIELD_VECTOR
   g_srv_velocity = datamap_offset("m_vecVelocity", 3);       // FIELD_VECTOR
-  g_srv_activeweapon = datamap_offset("m_hActiveWeapon", 13); // FIELD_EHANDLE
+  g_srv_activeweapon = datamap_offset("m_hActiveWeapon", FIELD_EHANDLE);
+  g_srv_relationship = datamap_offset("m_Relationship", FIELD_EMBEDDED);
+  g_srv_followtarget = datamap_offset("m_hFollowTarget", FIELD_EHANDLE);
   g_srv_ready = g_srv_health > 0;
   if (g_srv_ready) {
     logf("server datamap (%s): health=%d maxhealth=%d lifeste=%d "
-         "modelindex=%d absvel=%d vel=%d activeweapon=%d",
+         "modelindex=%d absvel=%d vel=%d activeweapon=%d relationship=%d "
+         "followtarget=%d",
          g_server.path.c_str(), g_srv_health, g_srv_maxhealth, g_srv_lifestate,
          g_srv_modelindex, g_srv_absvelocity, g_srv_velocity,
-         g_srv_activeweapon);
+         g_srv_activeweapon, g_srv_relationship, g_srv_followtarget);
     fail_logged = false;
   } else if (!fail_logged) {
     fail_logged = true;
@@ -189,6 +199,52 @@ int server_model_index(void *base) {
 // networked m_vecVelocity directly is deliberately avoided because the server
 // datamap scan can find a same-named field on another class first. The movement
 // code syncs m_vecVelocity through SetAbsVelocity after the command.
+// Server-side AI relationship (D_ER=0, D_HT=1, D_FR=2, D_LI=3, D_NU=4).
+// m_Relationship is a CUtlVector<Relationship_t>; each entry is
+// EHANDLE entity, Class_T classType, Disposition_t disposition, int priority.
+int server_npc_relation(int idx, int local_idx) {
+  if (!g_srv_ready || g_srv_relationship < 0 || local_idx <= 0)
+    return -1;
+  void *base = nullptr;
+  server_entity_health(idx, nullptr, nullptr, &base);
+  if (!base)
+    return -1;
+  uintptr_t rel = (uintptr_t)base + g_srv_relationship;
+  int count = *(int *)(rel + 12);
+  if (count <= 0 || count > 64)
+    return -1;
+  uintptr_t elems = *(uintptr_t *)(rel + 16);
+  if (!elems)
+    elems = *(uintptr_t *)(rel + 0);
+  if (!elems || (elems & 3))
+    return -1;
+  int class_relation = -1;
+  for (int i = 0; i < count; i++) {
+    uintptr_t e = elems + (uintptr_t)i * 16;
+    uint32_t h = *(uint32_t *)(e + 0);
+    int class_type = *(int *)(e + 4);
+    int disposition = *(int *)(e + 8);
+    if (h != 0 && h != 0xFFFFFFFFu) {
+      if ((int)(h & 0x7FF) == local_idx)
+        return disposition;
+    } else if (class_type == 1) { // CLASS_PLAYER
+      class_relation = disposition;
+    }
+  }
+  return class_relation;
+}
+
+bool server_npc_has_follow_target(int idx) {
+  if (!g_srv_ready || g_srv_followtarget < 0)
+    return false;
+  void *base = nullptr;
+  server_entity_health(idx, nullptr, nullptr, &base);
+  if (!base)
+    return false;
+  uint32_t h = *(uint32_t *)((uintptr_t)base + g_srv_followtarget);
+  return h != 0 && h != 0xFFFFFFFFu;
+}
+
 bool server_set_velocity_z(int idx, float vz) {
   if (!g_srv_ready || !g_iface.engineserver || g_srv_absvelocity <= 0)
     return false;