fix(simulation): Clippy cleanup and CI enforcement (#635)

Fix all Clippy warnings across the server codebase (2411 insertions, 1341
deletions). Raise type-complexity-threshold to 750 and too-many-arguments
to 12 in .clippy.toml for idiomatic Bevy ECS system signatures. The server
now passes `cargo clippy -- --deny warnings` cleanly.

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

server/src/simulation/follow.rs

@@ -13,11 +13,11 @@
 
 use bevy_ecs::prelude::*;
 
+use crate::npc::tolerance::ToleranceBreached;
 use crate::npc::{Npc, ToleranceThreshold};
 use crate::perception::query::VisibilityGeometry;
 use crate::simulation::movement::{PlayerCharacter, TilePosition};
 use crate::simulation::time::SimulationTime;
-use crate::npc::tolerance::ToleranceBreached;
 
 // ---------------------------------------------------------------------------
 // Constants
@@ -783,7 +783,10 @@ mod tests {
     #[test]
     fn follow_constants_have_expected_values() {
         // Spec-defined in #241 — changes here break the design contract
-        assert_eq!(FOLLOW_PROXIMITY_RANGE, 2, "D-241: 'too close' range is 2 Manhattan tiles");
+        assert_eq!(
+            FOLLOW_PROXIMITY_RANGE, 2,
+            "D-241: 'too close' range is 2 Manhattan tiles"
+        );
         assert_eq!(
             FOLLOW_SUSPICION_TICKS, 60,
             "D-241: suspicion starts after 60 sustained proximity ticks"