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/.clippy.toml

@@ -7,3 +7,9 @@ disallowed-types = [
     { path = "std::collections::HashMap", reason = "HashMap iteration order is non-deterministic. Use BTreeMap or IndexMap for deterministic simulation." },
     { path = "std::collections::HashSet", reason = "HashSet iteration order is non-deterministic. Use BTreeSet or IndexSet." },
 ]
+
+# Bevy ECS system functions naturally accumulate many Res<>/Query<> parameters and
+# complex Query type signatures. These thresholds are tuned to allow idiomatic
+# Bevy system code while still catching genuinely problematic complexity elsewhere.
+type-complexity-threshold = 750
+too-many-arguments-threshold = 12