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/settings/mod.rs

@@ -192,11 +192,11 @@ pub struct SettingsPlugin;
 
 impl Plugin for SettingsPlugin {
     fn build(&self, app: &mut App) {
+        use crate::tick_phases::TickPhase;
+
         app.init_resource::<SettingsCommandBuffer>().add_systems(
             Update,
-            process_settings_commands
-                .after(crate::simulation::input::process_player_input)
-                .before(crate::perception::observer::compute_observer_snapshot),
+            process_settings_commands.in_set(TickPhase::Snapshot),
         );
         tracing::debug!("SettingsPlugin initialized");
     }