ESP: classify NPC damage immunity/armour/vulnerability

- Resolve server m_takedamage (DAMAGE_NO/DAMAGE_EVENTS_ONLY = immune).
- Classify gunship/strider/dropship as ARMORED (OnTakeDamage only accepts
  DMG_BLAST; only the RPG passes), and headcrab/antlion/manhack as VULN
  (gravity gun / physics impact).
- ESP draws ARMORED/VULN/IMMUNE tags above the name (new "Damage tags"
  toggle, [esp] dmg).
- Aimbot, silent aim, triggerbot and melee skip immune targets and armoured
  targets unless the active weapon is the RPG.

1 files changed, 18 insertions, 0 deletions

diff --git a/CONTEXT.md b/CONTEXT.md
index 2199be6..7f8b131 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -188,6 +188,24 @@ vocabulary / decisions.
   not aimbot targets and draw with the neutral colour. Lamarr
   (`models/Lamarr.mdl`) is additionally listed as neutral by model.
 
+## Damage classification
+
+- Every NPC is classified for ESP and target selection:
+  - `IMMUNE` — server `m_takedamage` is `DAMAGE_NO`/`DAMAGE_EVENTS_ONLY`.
+  - `ARMORED` — gunship, strider, dropship: their `OnTakeDamage` only accepts
+    blast damage (`DMG_BLAST`, with a damage threshold on gunships and a
+    distance check on striders). Only the RPG passes; bullets/grenades do not.
+  - `VULNERABLE` — headcrab, antlion, manhack: punting them with the gravity
+    gun / physics impact damage kills them.
+  - `NORMAL` — everything else.
+- ESP draws `ARMORED` (orange), `VULN` (cyan) or `IMMUNE` (grey) above the
+  name; toggle is `ESP → Damage tags` (`[esp] dmg=1`).
+- Aimbot/silent aim/triggerbot/melee skip `IMMUNE` targets always and
+  `ARMORED` targets unless the active weapon is the RPG
+  (`active_weapon_contains` for `rocket_launcher`/`rpg`).
+- Server `m_takedamage` (`FIELD_INTEGER`) is resolved alongside
+  `m_NPCState`; `0/1` means no damage.
+
 ## Bones / ESP
 
 - `SetupBones(BONE_USED_BY_ANYTHING)` with engine `Time()`; studio header via