Reorganiza backend

backend/app/pipelines/layout_spiral.py

@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+import math
+
+
+def spiral_positions(n: int, *, max_r: float = 5000.0) -> tuple[list[float], list[float]]:
+    """
+    Deterministic "sunflower" (golden-angle) spiral layout.
+
+    This is intentionally simple and stable across runs:
+    - angle increments by the golden angle to avoid radial spokes
+    - radius grows with sqrt(i) to keep density roughly uniform over area
+    """
+    if n <= 0:
+        return ([], [])
+
+    xs = [0.0] * n
+    ys = [0.0] * n
+
+    golden = math.pi * (3.0 - math.sqrt(5.0))
+    denom = float(max(1, n - 1))
+
+    for i in range(n):
+        t = i * golden
+        r = math.sqrt(i / denom) * max_r
+        xs[i] = r * math.cos(t)
+        ys[i] = r * math.sin(t)
+
+    return xs, ys
+