feat(layout): relax MAM_MIN_PANE_COLS to 15 and remove vertical height constraints for scrollable terminal split

.agents/skills/lib_py/layout.py

@@ -70,8 +70,8 @@ def extract_panes(data: Dict[str, Any]) -> List[PaneInfo]:
 
 def compute_2xk_layout(
     data: Dict[str, Any],
-    min_cols: int = 40,
-    min_rows: int = 20,
+    min_cols: int = 15,
+    min_rows: int = 0,
     max_columns: Optional[int] = None,
     default_anchor_id: Optional[str] = None
 ) -> LayoutDecision:
@@ -90,8 +90,8 @@ def compute_2xk_layout(
     if len(panes) == 1:
         p = panes[0]
         # In 2xK grid, 1 pane -> 2 panes: split down to create top and bottom rows
-        # Check height overflow if dimensions known
-        if p.height > 0 and p.height // 2 < min_rows:
+        # Check height overflow only if min_rows > 0 is explicitly configured
+        if min_rows > 0 and p.height > 0 and p.height // 2 < min_rows:
             # If height is too small for 2 rows, try splitting right if width allows
             if p.width > 0 and p.width // 2 >= min_cols:
                 return LayoutDecision(target_pane_id=p.pane_id, direction="right", reason="single_pane_height_constrained")
@@ -153,8 +153,8 @@ def compute_2xk_layout(
 
     if singleton_col is not None:
         target_p = singleton_col[0]
-        # Check height
-        if target_p.height > 0 and target_p.height // 2 < min_rows:
+        # Check height only if min_rows > 0
+        if min_rows > 0 and target_p.height > 0 and target_p.height // 2 < min_rows:
             return LayoutDecision(target_pane_id=target_p.pane_id, direction="overflow", is_overflow=True, reason="singleton_height_overflow")
         return LayoutDecision(target_pane_id=target_p.pane_id, direction="down", reason="fill_singleton_column")
 
@@ -176,7 +176,7 @@ def _env_int(*names: str, default: Optional[int] = None) -> Optional[int]:
     """First *valid* int among the env vars in *names*, else `default`.
 
     `default` is an explicit parameter rather than an `or` at the call site so a
-    legitimate 0 survives (MAM_MIN_PANE_COLS=0 means 0, not the 40 default).
+    legitimate 0 survives (MAM_MIN_PANE_COLS=0 means 0, not the 15 default).
 
     An unparsable value is skipped rather than raised or treated as terminal: a
     typo in an operator's shell must not take the whole layout call down (lib.sh
@@ -198,8 +198,8 @@ def _env_int(*names: str, default: Optional[int] = None) -> Optional[int]:
 
 def main():
     parser = argparse.ArgumentParser(description="Compute 2xK grid TUI layout split direction")
-    parser.add_argument("--min-cols", type=int, default=_env_int("MAM_MIN_COLS", "MAM_MIN_PANE_COLS", default=40))
-    parser.add_argument("--min-rows", type=int, default=_env_int("MAM_MIN_ROWS", "MAM_MIN_PANE_ROWS", default=20))
+    parser.add_argument("--min-cols", type=int, default=_env_int("MAM_MIN_COLS", "MAM_MIN_PANE_COLS", default=15))
+    parser.add_argument("--min-rows", type=int, default=_env_int("MAM_MIN_ROWS", "MAM_MIN_PANE_ROWS", default=0))
     parser.add_argument("--max-cols", type=int, default=_env_int("MAM_MAX_COLS", "MAM_MAX_PANE_COLS"))
     parser.add_argument("--sample-pane", type=str, default=None)
     parser.add_argument("--json", action="store_true", help="Output full JSON decision")