refactor(simulation): replace ad-hoc system ordering with TickPhase pipeline (#843)

10-phase linear pipeline: PreInput → Input → Movement → Simulation →
Economy → Storyteller → Snapshot → PostSnapshot → Knowledge → TickAdvance.

Each system assigned to exactly one phase via .in_set(TickPhase::X).
Cross-phase .after()/.before() eliminated — only intra-phase ordering
remains. Prevents schedule cycles by construction.

SimulationPlugin refactored into sub-plugins by domain:
  - InputPlugin (player actions, interactions, dialogue dispatch)
  - MovementPlugin (pathfinding, movement validation, spatial indexing)
  - SocialPlugin (conversations, sound, voice enrichment, follow state)
  - EconomyPlugin (tâtonnement tick, IPC query serving)
  - TimePlugin (chunk streaming, news ticker, tick advancement)

All other plugins (NPC, Knowledge, Perception, Storyteller, Settings,
Bridge) updated to use TickPhase assignments instead of cross-plugin
ordering constraints. BridgePlugin trimmed to bridge I/O concerns only.

Part A of #843. Parts B (multi-threaded executor) and C (background
workers) follow.

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

server/src/simulation/movement_plugin.rs

@@ -0,0 +1,41 @@
+//! Movement phase plugin — position resolution and spatial indexing.
+//!
+//! All systems run in [`TickPhase::Movement`]. Intra-phase ordering:
+//! - pathfinding → follow_paths → validate_movement → cleanup_path_blocked
+//! - After validate_movement: spatial index, listening focus, zone crossings, tier systems
+
+use bevy_app::prelude::*;
+use bevy_ecs::schedule::IntoScheduleConfigs;
+
+use crate::tick_phases::TickPhase;
+
+pub struct MovementPlugin;
+
+impl Plugin for MovementPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<super::spatial::NaiveSpatialIndex>()
+            .init_resource::<super::zone::ZoneCrossEventQueue>()
+            .init_resource::<super::zone::PreviousPlayerZone>()
+            .add_systems(
+                Update,
+                (
+                    // Core movement chain (strict sequence)
+                    super::pathfinding::compute_paths,
+                    super::path_follow::follow_paths
+                        .after(super::pathfinding::compute_paths),
+                    super::movement::validate_movement
+                        .after(super::path_follow::follow_paths),
+                    super::path_follow::cleanup_path_blocked
+                        .after(super::movement::validate_movement),
+                    // Post-movement indexing (all after validate_movement, parallel with each other)
+                    super::spatial::sync_spatial_index
+                        .after(super::movement::validate_movement),
+                    super::listening::update_listening_focus
+                        .after(super::movement::validate_movement),
+                    super::zone::detect_zone_crossings
+                        .after(super::movement::validate_movement),
+                )
+                    .in_set(TickPhase::Movement),
+            );
+    }
+}