feat(simulation): ban HashMap via clippy disallowed_types, fix violations (#343)

Adds server/.clippy.toml with disallowed-types for std::collections::HashMap
and std::collections::HashSet. HashMap iteration order is non-deterministic
and breaks deterministic simulation replay (D-030).

Changes:
- server/.clippy.toml: disallow HashMap and HashSet crate-wide
- simulation/movement.rs: WalkabilityMap.chunks and occupied map → BTreeMap;
  add PartialOrd+Ord to ChunkCoord, TilePosition, TilePresence
- simulation/monologue.rs: MonologueState.shown_ids → BTreeSet (simulation state)
- perception/shadowcast.rs: #![allow] — per-frame FOV scratch, iteration irrelevant
- perception/interpretation.rs: #![allow] — per-frame lookup table, key-only access
- perception/query.rs: #![allow] — sector_lookup is a per-frame read-only cache

Also applies cargo fmt to pre-existing format drift in contraband.rs,
dialogue.rs, test_world/mod.rs, and several integration tests.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/src/test_world/mod.rs

@@ -52,13 +52,13 @@ use crate::perception::cognitive_delay::CognitiveDelay;
 #[cfg(feature = "gauntlet")]
 use crate::perception::vision_cone::Facing;
 #[cfg(feature = "gauntlet")]
+use crate::simulation::contraband::ScanEventBuffer;
+#[cfg(feature = "gauntlet")]
 use crate::simulation::interaction::{Interactable, NearbyInteractionBuffer};
 #[cfg(feature = "gauntlet")]
 use crate::simulation::inventory::ItemName;
 #[cfg(feature = "gauntlet")]
 use crate::simulation::listening::ListeningFocus;
-#[cfg(feature = "gauntlet")]
-use crate::simulation::contraband::ScanEventBuffer;
 use crate::simulation::monologue::{MonologueBuffer, MonologueState, SprintAnomalyQueue};
 #[cfg(feature = "gauntlet")]
 use crate::simulation::movement::{PlayerCharacter, TilePosition, WalkabilityMap};