Fix audit findings: crash safety, correctness, rendering, performance

Crash/UB:
- gate every hook behind an init-stage flag until config/surface/input are ready
- publish module maps as immutable atomic snapshots instead of reallocating
  shared vectors under unlocked readers
- validate the %ebp walk in the RandomSeed/RandomFloat hooks against the stack
- bounds-check every RecvTable/RecvProp/string dereference with module_range()
- preserve the Itanium vtable header when cloning (client, CInput, model render,
  studio render)
- reject negative usercmd sequence numbers; guard config_load against a null
  section target; cap the bone parent walk; check mprotect; drop PROT_EXEC on
  the GOT patch; absorb server.so .bss tail

Correctness:
- filter dormant entities across ESP, aimbot, triggerbot, melee, items and
  projectiles (slot self-tested against the local player)
- reset the server-health latch per map and only latch on valid model indices
- bone cache sized for the 128-target scan; set valid=false on every failure;
  head_position keeps searching past an invalid bone
- vischeck steps past glass by probing until clear, and ignores entities owned
  by the target (held weapons, bone followers)
- aimbot: maxs no longer disables it, AABB-aware FOV prefilter, lock hysteresis,
  lead point re-checked for FOV and visibility
- spread: seed hook arms on the no-spread toggle alone; engine toggle only
  controls the RandomFloat zeroing
- resolve m_hOwnerEntity/m_hOwner; NPC lead velocity from the server entity
- vector_angles pitch range, point_ground normal test, underwater jump+duck no
  longer skips combat, semi-auto press/release edge for synthetic fire
- item/projectile markers and blast rings refresh origin per frame while
  discovery stays at 10 Hz; trajectory uses the real m_DmgRadius and honours
  the blast-radius toggle

Rendering/GUI:
- one overlay draw per engine frame (FRAME_RENDER_START boundary), fixing
  alpha stacking and the speed-graph flicker
- clipped lines/outlines and ellipsised text instead of drawing past the
  content pane or shifting over neighbours
- dropdown dismissal consumes the click; hover ignores hidden controls
- chams: reset AlphaModulate, reference shared materials once, restore prop
  tint colour; fonts created once per handle
- projection uses Source's 4:3 aspect scaling and roll; screen size refreshed
  each frame; FOV circle gated on the aim toggles, not the bind

Performance:
- TTL caches for NPC relation, friendly/neutral and damage class
- model names memoised per model index
- entity pointer -> index cache for the triggerbot (was a 4096-slot walk/tick)

Build:
- real Makefile with -MMD dependency tracking, debug/release objects and an
  always-relink rule; build.sh kept as a thin wrapper

1 files changed, 140 insertions, 0 deletions

diff --git a/src/overlay.cpp b/src/overlay.cpp
new file mode 100644
index 0000000..2445d95
--- /dev/null
+++ b/src/overlay.cpp
@@ -0,0 +1,140 @@
+// overlay.cpp — the single ISurface access layer.
+#include "hl2h.h"
+#include <ctime>
+
+ISurface *g_surface = nullptr;
+
+// ---------------------------------------------------------------------------
+// per-frame draw budget
+// ---------------------------------------------------------------------------
+
+static bool g_drawn_this_frame = false;
+static double g_frame_mark_at = 0.0;
+
+static double overlay_now() {
+  timespec ts;
+  clock_gettime(CLOCK_MONOTONIC, &ts);
+  return (double)ts.tv_sec + (double)ts.tv_nsec * 1e-9;
+}
+
+void overlay_frame_mark() {
+  g_drawn_this_frame = false;
+  g_frame_mark_at = overlay_now();
+}
+
+bool overlay_should_draw() {
+  if (g_drawn_this_frame && overlay_now() - g_frame_mark_at < 0.10)
+    return false;
+  g_drawn_this_frame = true;
+  return true;
+}
+
+void overlay_color(int r, int g, int b, int a) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int, int, int, int);
+  vfunc<Fn>(g_surface, SURF_DrawSetColor)(g_surface, r, g, b, a);
+}
+
+void overlay_fill(int x0, int y0, int x1, int y1) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int, int, int, int);
+  vfunc<Fn>(g_surface, SURF_DrawFilledRect)(g_surface, x0, y0, x1, y1);
+}
+
+void overlay_outline_rect(int x0, int y0, int x1, int y1) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int, int, int, int);
+  vfunc<Fn>(g_surface, SURF_DrawOutlinedRect)(g_surface, x0, y0, x1, y1);
+}
+
+void overlay_line(int x0, int y0, int x1, int y1) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int, int, int, int);
+  vfunc<Fn>(g_surface, SURF_DrawLine)(g_surface, x0, y0, x1, y1);
+}
+
+void overlay_text_font(HFont f) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, HFont);
+  vfunc<Fn>(g_surface, SURF_DrawSetTextFont)(g_surface, f);
+}
+
+void overlay_text_color(int r, int g, int b, int a) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int, int, int, int);
+  vfunc<Fn>(g_surface, SURF_DrawSetTextColor)(g_surface, r, g, b, a);
+}
+
+void overlay_text_pos(int x, int y) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int, int);
+  vfunc<Fn>(g_surface, SURF_DrawSetTextPos)(g_surface, x, y);
+}
+
+void overlay_print_text(const wchar_t *text, int count, int draw_type) {
+  if (!g_surface || !text || count <= 0)
+    return;
+  using Fn = void (*)(void *, const wchar_t *, int, int);
+  vfunc<Fn>(g_surface, SURF_DrawPrintText)(g_surface, text, count, draw_type);
+}
+
+HFont overlay_create_font() {
+  if (!g_surface)
+    return 0;
+  using Fn = HFont (*)(void *);
+  return vfunc<Fn>(g_surface, SURF_CreateFont)(g_surface);
+}
+
+bool overlay_add_glyph_set(HFont f, const char *name, int tall, int weight,
+                           int blur, int scanlines, int flags, int range_min,
+                           int range_max) {
+  if (!g_surface || !name)
+    return false;
+  using Fn = bool (*)(void *, HFont, const char *, int, int, int, int, int, int,
+                      int);
+  return vfunc<Fn>(g_surface, SURF_AddGlyphSetToFont)(
+      g_surface, f, name, tall, weight, blur, scanlines, flags, range_min,
+      range_max);
+}
+
+void overlay_screen_size(int &w, int &h) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int &, int &);
+  vfunc<Fn>(g_surface, SURF_GetScreenSize)(g_surface, w, h);
+}
+
+void overlay_text_size(HFont f, const wchar_t *text, int &w, int &h) {
+  if (!g_surface || !text)
+    return;
+  using Fn = void (*)(void *, HFont, const wchar_t *, int &, int &);
+  vfunc<Fn>(g_surface, SURF_GetTextSize)(g_surface, f, text, w, h);
+}
+
+int overlay_embedded_panel() {
+  if (!g_surface)
+    return 0;
+  using Fn = int (*)(void *);
+  return vfunc<Fn>(g_surface, SURF_GetEmbeddedPanel)(g_surface);
+}
+
+void overlay_push_make_current(int panel, bool use_insets) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int, bool);
+  vfunc<Fn>(g_surface, SURF_PushMakeCurrent)(g_surface, panel, use_insets);
+}
+
+void overlay_pop_make_current(int panel) {
+  if (!g_surface)
+    return;
+  using Fn = void (*)(void *, int);
+  vfunc<Fn>(g_surface, SURF_PopMakeCurrent)(g_surface, panel);
+}