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/knowledge/events.rs

@@ -197,8 +197,7 @@ pub fn process_knowledge_events(
         match event.event_type {
             KnowledgeEventType::DirectObservation { target, position } => {
                 if let Some(stable_id) = registry.to_stable(target) {
-                    if let Some(claim) =
-                        observer_kg.observe_entity(stable_id, position, event.tick)
+                    if let Some(claim) = observer_kg.observe_entity(stable_id, position, event.tick)
                     {
                         // StableId is Copy — capture before moving claim into event.
                         let told_by = claim.told_by;