fix(simulation): resolve clippy warnings in atlas modules

Replace HashMap/HashSet with BTreeMap/BTreeSet per D-030 determinism
rule. Fix while_let_loop, map_or simplification, collapsible if,
unsigned_abs casting, iterator indexing, and redundant wildcard arms.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/atlas/attractor_matching.rs

@@ -69,7 +69,7 @@ fn role_row(economic_role: &str) -> usize {
         "transit_hub" => 6,
         "research" => 7,
         "military" => 8,
-        "residential" | _ => 9,
+        _ => 9,
     }
 }
 
@@ -132,8 +132,8 @@ fn hungarian(cost: &[Vec<f32>]) -> Vec<usize> {
             c[i][j] = cost[i][j];
         }
         // Pad extra columns with high cost so overflow cities pick them last.
-        for j in m..sz {
-            c[i][j] = f32::MAX / 2.0;
+        for item in c[i].iter_mut().take(sz).skip(m) {
+            *item = f32::MAX / 2.0;
         }
     }
     // Pad extra rows with 0 cost (dummy workers).
@@ -228,8 +228,8 @@ fn synthetic_attractor(
             let r = (dr * MIN_SPACING).min(grid_h as u16 - 1);
             let c = (dc * MIN_SPACING).min(grid_w as u16 - 1);
             let ok = placed.iter().all(|p| {
-                let dr2 = (p.position.0 as i32 - r as i32).abs() as u16;
-                let dc2 = (p.position.1 as i32 - c as i32).abs() as u16;
+                let dr2 = (p.position.0 as i32 - r as i32).unsigned_abs() as u16;
+                let dc2 = (p.position.1 as i32 - c as i32).unsigned_abs() as u16;
                 dr2.max(dc2) >= MIN_SPACING
             });
             if ok {
@@ -379,7 +379,7 @@ pub fn match_cities(
     // -------------------------------------------------------------------------
     // Phase 4: Synthetic overflow — all remaining cities
     // -------------------------------------------------------------------------
-    let placed_ids: std::collections::HashSet<u64> =
+    let placed_ids: std::collections::BTreeSet<u64> =
         placements.iter().map(|p| p.city_id).collect();
 
     for city in cities {
@@ -401,7 +401,7 @@ pub fn match_cities(
     // -------------------------------------------------------------------------
     // Phase 5: Name fulfillment check
     // -------------------------------------------------------------------------
-    let placed_ids: std::collections::HashSet<u64> =
+    let placed_ids: std::collections::BTreeSet<u64> =
         placements.iter().map(|p| p.city_id).collect();
     for city in cities {
         if !placed_ids.contains(&city.city_id) {