feat: implement ground state movement logic for player character

movement/states/state_ground.gd

@@ -79,7 +79,9 @@ func update(delta: float) -> void:
 		vel.y -= params.gravity * delta
 	else:
 		# Snap to floor: small downward velocity keeps is_on_floor() stable
-		vel.y = -0.5
+		# ONLY if we aren't being launched upward by an impulse!
+		if vel.y <= 0.0:
+			vel.y = -0.5
 
 	player.velocity = vel
 	player.move_and_slide()
@@ -93,10 +95,11 @@ func update(delta: float) -> void:
 	else:
 		machine.on_ground = false
 
-	# ── Falling off ledge → air state ─────────────────────────────────────
-	if not machine.on_ground and machine.coyote_timer <= 0.0:
-		machine.switch_to("air")
-		return
+	# ── Launch or Falling off ledge → air state ───────────────────────────
+	if not machine.on_ground:
+		if player.velocity.y > 0.0 or machine.coyote_timer <= 0.0:
+			machine.switch_to("air")
+			return
 
 	# ── Wall run check ────────────────────────────────────────────────────
 	var wall_n := machine.detect_wall_horizontal()