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, 14 insertions, 1 deletions

diff --git a/src/gui.cpp b/src/gui.cpp
index 59c4364..2f832a2 100644
--- a/src/gui.cpp
+++ b/src/gui.cpp
@@ -364,7 +364,9 @@ static void build_cards() {
   add_card(1, &g_triggerbot, "Triggerbot",
            "Fire when the crosshair is on a hostile.", true);
 
-  add_card(1, &g_melee, "Melee killbot", "360-degree crowbar silent aim.",
+  add_card(1, &g_melee, "Melee killbot",
+           "360-degree crowbar swing, or a gravity-gun launch at VULN "
+           "targets while holding an object.",
            true);
 
   int esp = add_card(2, &g_esp, "ESP", "Draw hostile NPC information.", true);
@@ -405,11 +407,22 @@ static void build_cards() {
              &g_item_crates);
   add_toggle(items, "Show distance", "Append the distance in units.",
              &g_item_distance);
+  add_toggle(items, "Only if usable",
+             "Hide health kits at full health and armor at full suit.",
+             &g_item_usable);
   add_slider(items, "Max distance",
              "0 = unlimited; otherwise items farther away are hidden.", 0,
              10000, &g_item_max_dist);
   g_ctrls[g_nctrl - 1].zero_unlimited = true;
 
+  int proj = add_card(2, &g_projectiles, "Projectiles",
+                      "Tag grenades, rockets, bombs and AR2 balls.", true);
+  add_toggle(proj, "Fuse timer",
+             "Show the remaining time until a grenade or ball detonates.",
+             &g_proj_fuse);
+  add_toggle(proj, "Blast radius",
+             "Draw the projectile's damage radius on the ground.", &g_proj_radius);
+
   int view = add_card(2, nullptr, "Camera / display",
                       "Camera FOV, viewmodel FOV and HDR brightness.", true);
   add_slider(view, "Camera FOV",