Jumpbug: automatic duck+jump on damaging falls

- Predict the landing speed from the current vertical velocity and a swept
  standing-hull ground trace; engage only when it exceeds
  PLAYER_MAX_SAFE_FALL_SPEED.
- Press duck one command before the unduck window so FinishDuck's 36-unit
  origin raise places the feet ~37 units above the floor.
- On the next command release duck and press jump: PlayerMove runs Duck()
  before CheckJumpButton, so FinishUnDuck sets ground, the jump executes, and
  CheckFalling never sees ground for the fall-damage check.
- Measure the per-command fall from consecutive airborne origins instead of a
  fixed tick interval; clear IN_JUMP while waiting so the pogo latch is clear.
- New Movement -> Jumpbug -> Active toggle (default on), config [jumpbug].

1 files changed, 27 insertions, 3 deletions

diff --git a/CONTEXT.md b/CONTEXT.md
index cd3811d..b1ec4e7 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -104,21 +104,26 @@ HL2hake
     Uni-directional auto-strafe
   ABH
     Active
+  Jumpbug
+    Active
   ESP
     Active
-    Show neutral / healthbar / healthnum / name / skeleton / box
+    Show neutral / healthbar / healthnum / name / skeleton / box / speed graph
   Aimbot
     Active
     Bind
     Vischeck
     Bones -> Head / Torso / Left arm / Right arm / Left leg / Right leg
     Smoothness (1..45 deg/tick, Left/Right)
+    FOV (1..180 deg, Left/Right)
+    Show FOV circle
   Triggerbot
     Active
     Bind
   Silent aim
     Active
     Bind
+    FOV (1..180 deg, Left/Right)
 ```
 
 Binds use SDL scancodes; mouse buttons are pseudo-scancodes 600..604.
@@ -156,6 +161,27 @@ Binds use SDL scancodes; mouse buttons are pseudo-scancodes 600..604.
   zero forward/side movement; HL2's jump speed-bound subtraction then
   accelerates along the velocity. Camera restored at `FRAME_RENDER_START`.
 
+## Jumpbug
+
+- Automatic while falling when the predicted landing speed
+  `sqrt(vz^2 + 2*600*x)` exceeds `PLAYER_MAX_SAFE_FALL_SPEED` (526.5).
+- The engine only applies fall damage when `CheckFalling` sees a ground entity
+  at the end of the frame. `PlayerMove` runs `Duck()` **before**
+  `FullWalkMove`'s `CheckJumpButton`, so a same-frame `FinishUnDuck` sets ground
+  via `CategorizePosition`, the jump executes, and the fall-damage test is
+  skipped.
+- In air, `FinishDuck` raises the origin by 36 (standing hull 72, duck hull 36)
+  and `CanUnduck` only succeeds when the floor is at least 36 below; after
+  unducking, `CategorizePosition` needs it within 2 more units. The unduck
+  window is therefore a 2-unit band `[36,38]` above the floor.
+- The feature presses duck when the standing distance `x` is within
+  `drop + [0,2]` (where `drop` is the previous command's measured fall), then
+  releases duck + `IN_JUMP` on the next command when `x` is in `[36,38]`.
+  It also clears `IN_JUMP` while waiting so the pogo latch is clear.
+- `drop` is measured from consecutive predicted origins (not a hard-coded tick
+  interval). At high fall speeds the 2-unit band can be skipped between
+  commands; a higher frame rate improves reliability. Best-effort by design.
+
 ## Gotchas / lessons
 
 - Never pipe-mask build failures:
@@ -171,8 +197,6 @@ Binds use SDL scancodes; mouse buttons are pseudo-scancodes 600..604.
 
 - **Melee killbot**: 360° silent aim for hostile NPCs inside crowbar/melee
   range, sorted by distance, only while the crowbar is held.
-- **Jumpbug**: automate the HL2 jumpbug movement glitch (trigger conditions
-  to be defined/tested).
 - **GUI**: replace/augment the VGUI ISurface menu with an immediate-mode GUI
   (Dear ImGui or a custom implementation); needs a design grill first.
 - **Distance weapon spread thesis**: TBD — user will explain. Likely models