Fix: Wal springt nicht mehr, Farben korrekt

Alle 12 Frames normalisiert auf 8 Zeilen (3 Fontäne + 1 Separator + 4 Körper).
Vorher variierten die Frame-Höhen (6–8 Zeilen), sodass der Körper zwischen
Zeilen 2/3/4 sprang. Maske hatte 7 Zeilen → bei 8-Zeilen-Frames um 1 Zeile
versetzt → falsche Körperfarben.

- mask_r/l: leere Trennzeile zwischen Fontänen-Farben und Körper-Farben
- Fontänen-Zeilen auf genau 3 aufgefüllt (oben mit Leerstrings)
- Frames direkt als Listen gebaut statt über _p()-String-Konkatenation

Außerdem aus vorheriger Session:
- add_all_fish: Anzahl relativ zu wl (statt hardcodiert)
- main: Terminalgröße erst nach ALT_ON lesen (Split-Pane-Fix)
- --debug Flag

asciiquarium_ng.py

@@ -473,7 +473,8 @@ class Aquarium:
     # ── Fish ─────────────────────────────────────────────────────────────────
 
     def add_all_fish(self):
-        count = max(8, (self.rows - 9) * self.cols // 200)
+        underwater_rows = max(1, self.rows - (self.wl + 4))
+        count = max(15, underwater_rows * self.cols // 120)
         for _ in range(count):
             self.add_fish(None)
 
@@ -859,6 +860,7 @@ yywwwyyyyyyyyyyyyyyyyyyyy
              C C
            CCCCCCC
            C  C  C
+
         BBBBBBB
       BB       BB
 B    B       BWB B
@@ -868,6 +870,7 @@ BBBBB          BBBB
    C C
  CCCCCCC
  C  C  C
+
     BBBBBBB
   BB       BB
  B BWB       B    B
@@ -890,17 +893,24 @@ BBBB          BBBBB
         mask_str    = mask_r_str if going_right else mask_l_str
         x = -18 if going_right else self.cols - 2
 
+        # 4 body lines; all frames are 8 rows: 3 spout + 1 separator + 4 body.
+        # This keeps the body at the same rows (4-7) in every frame so the
+        # whale doesn't jump, and the mask aligns correctly.
+        body_lines = _p(body_str)
+        mask_lines = _p(mask_str)
+
         frames, masks = [], []
-        # 5 frames without spout
+        # 5 frames without spout: 4 empty rows + 4 body rows
         for _ in range(5):
-            frames.append(_p('\n\n\n' + body_str))
-            masks.append(_p(mask_str))
-        # 7 frames with animated spout
+            frames.append(['', '', '', ''] + body_lines)
+            masks.append(mask_lines)
+        # 7 frames with animated spout: spout padded to 3 rows, then separator, then body
         for spout in spouts:
-            sp_lines = spout.strip('\n').split('\n')
-            aligned  = '\n'.join(' ' * spout_align + l for l in sp_lines)
-            frames.append(_p(aligned + '\n' + body_str))
-            masks.append(_p(mask_str))
+            sp_lines = [' ' * spout_align + l for l in spout.strip('\n').split('\n')]
+            while len(sp_lines) < 3:
+                sp_lines = [''] + sp_lines
+            frames.append(sp_lines + [''] + body_lines)
+            masks.append(mask_lines)
 
         self._add(Entity(
             frames=frames, masks=masks,
@@ -1544,6 +1554,8 @@ def main():
                         help='disable all predators (shark, big fish, fishhook)')
     parser.add_argument('--any-key',  action='store_true',
                         help='any key press exits (default: q/Q/Esc/Ctrl-C)')
+    parser.add_argument('--debug',    action='store_true',
+                        help='show terminal size / entity count overlay')
     args = parser.parse_args()
 
     cfg = Config(
@@ -1555,8 +1567,6 @@ def main():
         any_key  = args.any_key,
     )
 
-    rows, cols = term_size()
-    aq = Aquarium(rows, cols, cfg)
     inp = Input()
     paused = False
     needs_reset = False
@@ -1568,7 +1578,11 @@ def main():
     signal.signal(signal.SIGWINCH, on_resize)
 
     fd = sys.stdout.fileno()
+    # Activate alternate screen first, THEN read terminal size so the
+    # size reflects the actual pane dimensions (important in split panes).
     os.write(fd, (ALT_ON + HIDE_CUR + "\033[2J\033[H").encode())
+    rows, cols = term_size()
+    aq = Aquarium(rows, cols, cfg)
 
     try:
         TICK = 0.1 / cfg.speed
@@ -1595,6 +1609,13 @@ def main():
             if not paused:
                 aq.step()
                 frame = aq.render()
+                if args.debug:
+                    fish_ys = [f"{int(e.y)}" for e in aq.entities
+                               if e.entity_type == 'fish'][:8]
+                    dbg = (f" rows={aq.rows} cols={aq.cols} wl={aq.wl}"
+                           f" ents={len(aq.entities)}"
+                           f" fish_y=[{','.join(fish_ys)}] ")
+                    frame += f"\033[1;1H\033[0;7m{dbg}\033[m"
                 os.write(fd, frame.encode())
 
             elapsed = time.monotonic() - t0