Add usable item filter, projectile ESP and gravity-gun melee

- Items: "Only if usable" hides health tags at full health and armor at full
  suit. Health ceiling is the server player's m_iMaxHealth; armor uses the
  server m_ArmorValue against HL2's 100 cap. Fails open when unreadable.
- Projectiles: new Visuals feature/card for thrown grenades, RPG rockets,
  helicopter bombs and AR2 balls. Fuse from server m_flDetonateTime vs engine
  time; radius from m_DmgRadius with per-type fallback; optional 24-segment
  radius ring and FRAG timer label.
- Melee: the killbot now handles the gravity gun as well; only VULNERABLE
  targets, 1200-unit range, primary attack to launch the held object, and no
  aim-punch compensation because the launch uses EyeVectors.
- Server/netvars: m_ArmorValue, m_flDetonateTime, m_DmgRadius.

1 files changed, 35 insertions, 7 deletions

diff --git a/CONTEXT.md b/CONTEXT.md
index 5c91b5c..96a4660 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -310,10 +310,16 @@ vocabulary / decisions.
 
 ## Melee killbot
 
-- Active only while the local player's active weapon is the crowbar. The
-  client `m_hActiveWeapon` handle is used first; if it is missing, the
-  authoritative server `m_hActiveWeapon` handle (0x824) is used to get the
-  weapon entity index.
+- Active only while the local player's active weapon is the crowbar or the
+  gravity gun. The client `m_hActiveWeapon` handle is used first; if it is
+  missing, the authoritative server `m_hActiveWeapon` handle (0x824) is used
+  to get the weapon entity index.
+- With the gravity gun, only `VULNERABLE` targets (headcrab, antlion,
+  manhack) are selected, the range is 1200 units, and the attack button is
+  `IN_ATTACK`: the primary attack launches a held object along
+  `EyeVectors()`. No aim-punch compensation is applied there (EyeVectors does
+  not add punch); the crowbar path keeps it. Without a held object the primary
+  is a short physics punch.
 - Map transitions often switch the active weapon away from the crowbar. The
   state change is logged as `melee: active ... crowbar=0/1` (normal log), and
   a one-time toast says to equip the crowbar. If the client weapon model is
@@ -328,9 +334,9 @@ vocabulary / decisions.
   movement keys are rotated with `preserve_movement`, and the rendered view is
   restored immediately and at `FRAME_RENDER_START` (same silent-aim path).
   This gives a 360-degree silent melee attack.
-- While the crowbar is active and the killbot feature is on, the gun aimbot,
-  triggerbot and silent aim are skipped to avoid fighting over the usercmd
-  view.
+- While either melee weapon is active and the killbot feature is on, the gun
+  aimbot, triggerbot and silent aim are skipped to avoid fighting over the
+  usercmd view.
 - Vischeck uses the shared `MASK_VISIBLE`/world-only path (static props are
   ignored).
 
@@ -583,6 +589,11 @@ vocabulary / decisions.
 ## Valuable items
 
 - Visuals feature; Active is on by default and unbound (always-on).
+- "Only if usable" (`[items] usable=1`) hides health pickups when the local
+  player is at full health and armor pickups at full suit. The health ceiling
+  is the server player's `m_iMaxHealth` (not a hardcoded 100); armor uses the
+  HL2 `MAX_NORMAL_BATTERY` cap of 100, read from the server
+  `m_ArmorValue`. If the values cannot be read the filter fails open.
 - Scans the client entity list every 100 ms and tags health, ammo, armor/suit,
   world weapon pickups, the two supply-crate models and generic items.
 - Each tag is a colored marker with a name and optional distance, filtered by
@@ -601,6 +612,23 @@ vocabulary / decisions.
   item crates. The item scan falls back to the server entity's model index
   (`server_model_index`) to recover the model name.
 
+## Projectile ESP
+
+- Visuals feature `g_projectiles` (`[projectiles]`, Active on, unbound).
+- Scans the client entity list every 100 ms for world-model `w_grenade`,
+  `w_missile*`, `helicopter_bomb` and `combineball`. Weapon entities are
+  excluded by class (`...weapon...`); thrown grenades are recognised by
+  `CGrenadeFrag`-style class names or by an owner handle.
+- Fuse: `CBaseGrenade::m_flDetonateTime` is not networked, so it is read from
+  the server entity datamap (`FIELD_TIME`) and compared with
+  `IVEngineClient::Time()` (slot 14). RPG rockets have no fuse.
+- Blast radius: networked client `m_DmgRadius` when available, server
+  `m_DmgRadius` (`FIELD_FLOAT`) as fallback, then 300/200/150/300 for
+  frag/RPG/AR2/bomb.
+- Draws a small marker and a `FRAG 1.2s`-style label; the optional radius ring
+  is a 24-segment horizontal circle projected at the projectile height.
+  Toggles: Fuse timer, Blast radius.
+
 ## Roadmap / TODO
 
 - **Server-side spread/recoil control**: not planned; recoil and accuracy