fix(physics): disable playful biomechanics during aggressive ad skips

- Fixed a bug where `humanized_scroll(is_skip=True)` could trigger random 'Doomscroll Corrections' (scrolling backwards) or 'reading pauses'.
- This caused the Anti-Stuck loop for ads to fail because the aggressive skip would occasionally just pause or scroll back into the ad.
- Added strict TDD coverage in `test_physics_humanized.py` to verify `is_skip` generates strictly forward gestures without pauses.

GramAddict/core/physics/humanized_input.py

@@ -48,19 +48,12 @@ def humanized_scroll(device, is_skip=False, resonance_score=None):
     start_x, start_y = body.get_scroll_start()
     end_x = start_x + random.gauss(0, w * 0.008)  # Slight horizontal drift
 
-    do_correction = random.random() < correction_prob
-
     if is_skip:
-        # Aggressive fast fling to skip quickly
-        if do_correction:
-            logger.debug(f"🪀 [Doomscroll] Correction (Prob: {correction_prob:.2f}) — Wait, what was that?")
-            distance = int(h * random.uniform(0.3, 0.5))
-            duration = random.uniform(100, 150)
-            end_y = min(start_y + distance, h - 10)  # Move down to pull UI up
-        else:
-            distance = int(h * random.uniform(0.6, 0.75))
-            duration = random.uniform(100, 150)
-            end_y = start_y - distance
+        # Aggressive fast fling to skip quickly. NO CORRECTIONS.
+        distance = int(h * random.uniform(0.6, 0.75))
+        duration = random.uniform(150, 250) # slightly longer to ensure smooth fling registration
+        end_y = start_y - distance
+        do_correction = False # Force false
     else:
         # Playful, organic human scrolling
         play_choice = random.random()
@@ -97,7 +90,7 @@ def humanized_scroll(device, is_skip=False, resonance_score=None):
             end_y = start_y - distance
 
     # --- Behavioral Micro-Patterns (new human behaviors) ---
-    behavior = _select_scroll_behavior()
+    behavior = None if is_skip else _select_scroll_behavior()
 
     if behavior == "pre_touch_dwell":
         # Finger lands on glass before swiping (50-200ms dwell)

tests/unit/test_physics_humanized.py

@@ -46,3 +46,40 @@ def test_humanized_scroll_speeds(MockInjector):
     # Timing intervals must all be positive
     for t in timing:
         assert t > 0, f"Timing interval must be positive, got {t}"
+
+
+@patch("GramAddict.core.physics.humanized_input.SendEventInjector")
+def test_humanized_scroll_skip_is_strictly_forward(MockInjector):
+    """
+    Ensures that when is_skip=True (e.g. for aggressive ad skipping),
+    the generated gesture is purely forward (bottom to top swipe),
+    and does NOT contain backwards 'Doomscroll corrections' or 
+    biomechanical 'reading pauses'.
+    """
+    mock_injector = MagicMock()
+    MockInjector.get_instance.return_value = mock_injector
+
+    device = MagicMock()
+    device.get_info.return_value = {"displayHeight": 2400, "displayWidth": 1080}
+
+    from GramAddict.core.physics.humanized_input import humanized_scroll
+
+    # Run multiple times to overcome randomness in play_choice / do_correction
+    for _ in range(50):
+        mock_injector.reset_mock()
+        humanized_scroll(device, is_skip=True)
+        
+        args = mock_injector.inject_gesture.call_args
+        points = args[0][0]
+        timing = args[0][1]
+        
+        # In a forward scroll (bottom to top), the Y coordinate must go from a higher number to a lower number.
+        start_y = points[0][1]
+        end_y = points[-1][1]
+        
+        # End Y MUST be less than Start Y (meaning we scrolled down the feed, swiping finger up)
+        assert end_y < start_y, f"Expected end_y ({end_y}) to be < start_y ({start_y}) for a skip."
+        
+        # Verify no long pauses (reading pause adds 0.5s to 2.0s to timing)
+        for t in timing:
+            assert t < 500, "Found a massive pause in a skip gesture, meaning a reading_pause or dwell was incorrectly inserted!"