diff --git a/server/src/bin/aliveness_probe.rs b/server/src/bin/aliveness_probe.rs
index 2d0aabe19..74d5e1cad 100644
--- a/server/src/bin/aliveness_probe.rs
+++ b/server/src/bin/aliveness_probe.rs
@@ -605,48 +605,6 @@ fn encode_rgb_png(w: u32, h: u32, rgb: &[u8]) -> Vec<u8> {
     out
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// The palette is indexed by `MorphologyZone` discriminant (repr(u8),
-    /// append-only). Pinning the LAST variant's discriminant against the
-    /// palette length forces a palette extension — here AND in the client
-    /// source of truth (`atlas_marker_overlay.gd::MORPHOLOGY_COLORS`) — when
-    /// a zone is appended.
-    #[test]
-    fn morphology_palette_covers_every_zone() {
-        assert_eq!(MorphologyZone::Wetland as usize + 1, MORPHOLOGY_RGB.len());
-    }
-
-    /// `true_district_of_pixel` must invert `derive_district`'s forward mapping
-    /// (district → fractional working-grid position via the body radius) to
-    /// within the half-district rounding error — ≲0.01 working pixel at
-    /// planetary radii.
-    #[test]
-    fn true_district_inverts_forward_mapping() {
-        let (w, h) = (128usize, 64usize);
-        let r_km = 6371.0;
-        let circ_m = std::f64::consts::TAU * r_km * 1000.0;
-        let mer_m = std::f64::consts::PI * r_km * 1000.0;
-        for (row, col) in [(10u16, 100u16), (32, 0), (5, 127), (63, 64)] {
-            let (dx, dy) = true_district_of_pixel((row, col), w, h, Some(r_km));
-            let px = ((dx as f64 * scale::DISTRICT_M as f64) / circ_m).rem_euclid(1.0) * w as f64;
-            let py = (0.5 + ((dy as f64 * scale::DISTRICT_M as f64) / mer_m).clamp(-0.5, 0.5))
-                * (h - 1) as f64;
-            assert!((px - col as f64).abs() < 0.05, "px {px} vs col {col}");
-            assert!((py - row as f64).abs() < 0.05, "py {py} vs row {row}");
-        }
-    }
-
-    /// Without a radius the fallback maps pixel → district 1:1 (mirrors
-    /// `derive_district`'s tiny-test-body branch).
-    #[test]
-    fn true_district_fallback_is_identity() {
-        assert_eq!(true_district_of_pixel((7, 3), 128, 64, None), (3, 7));
-    }
-}
-
 // ---------------------------------------------------------------------------
 // Args
 // ---------------------------------------------------------------------------
@@ -694,3 +652,45 @@ impl Args {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// The palette is indexed by `MorphologyZone` discriminant (repr(u8),
+    /// append-only). Pinning the LAST variant's discriminant against the
+    /// palette length forces a palette extension — here AND in the client
+    /// source of truth (`atlas_marker_overlay.gd::MORPHOLOGY_COLORS`) — when
+    /// a zone is appended.
+    #[test]
+    fn morphology_palette_covers_every_zone() {
+        assert_eq!(MorphologyZone::Wetland as usize + 1, MORPHOLOGY_RGB.len());
+    }
+
+    /// `true_district_of_pixel` must invert `derive_district`'s forward mapping
+    /// (district → fractional working-grid position via the body radius) to
+    /// within the half-district rounding error — ≲0.01 working pixel at
+    /// planetary radii.
+    #[test]
+    fn true_district_inverts_forward_mapping() {
+        let (w, h) = (128usize, 64usize);
+        let r_km = 6371.0;
+        let circ_m = std::f64::consts::TAU * r_km * 1000.0;
+        let mer_m = std::f64::consts::PI * r_km * 1000.0;
+        for (row, col) in [(10u16, 100u16), (32, 0), (5, 127), (63, 64)] {
+            let (dx, dy) = true_district_of_pixel((row, col), w, h, Some(r_km));
+            let px = ((dx as f64 * scale::DISTRICT_M as f64) / circ_m).rem_euclid(1.0) * w as f64;
+            let py = (0.5 + ((dy as f64 * scale::DISTRICT_M as f64) / mer_m).clamp(-0.5, 0.5))
+                * (h - 1) as f64;
+            assert!((px - col as f64).abs() < 0.05, "px {px} vs col {col}");
+            assert!((py - row as f64).abs() < 0.05, "py {py} vs row {row}");
+        }
+    }
+
+    /// Without a radius the fallback maps pixel → district 1:1 (mirrors
+    /// `derive_district`'s tiny-test-body branch).
+    #[test]
+    fn true_district_fallback_is_identity() {
+        assert_eq!(true_district_of_pixel((7, 3), 128, 64, None), (3, 7));
+    }
+}