style(simulation): cargo fmt + fix clippy warnings after economics integration

- `economy.rs`: fix empty_line_after_doc_comments (section ordering),
  use `is_multiple_of` for ECON_TICK_RATE check
- `debug.rs`, `input.rs`, `mod.rs`: rustfmt import ordering + indentation

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

server/src/simulation/economy.rs

@@ -141,7 +141,7 @@ pub fn tick_economy_simulation(
         _ => return, // economy not loaded — no-op
     };
 
-    if time.tick % ECON_TICK_RATE != 0 {
+    if !time.tick.is_multiple_of(ECON_TICK_RATE) {
         return;
     }
 
@@ -196,9 +196,7 @@ fn rebuild_signals(
             let commodities: Vec<(String, f64, f64)> = node
                 .commodities
                 .iter()
-                .map(|(commodity_id, state)| {
-                    (commodity_id.clone(), state.price, state.supply)
-                })
+                .map(|(commodity_id, state)| (commodity_id.clone(), state.price, state.supply))
                 .collect();
             (system_id.clone(), commodities)
         })
@@ -280,15 +278,6 @@ fn rebuild_signals(
     }
 }
 
-// ---------------------------------------------------------------------------
-// Startup helper
-// ---------------------------------------------------------------------------
-
-/// Attempt to load the economy simulation.
-///
-/// Returns `Some((EconSimResource, EconStateResource))` on success, `None` on
-/// failure (with the error logged at warn level). The server inserts these as
-/// resources when present; the economy features degrade gracefully when absent.
 // ---------------------------------------------------------------------------
 // IPC query buffer (#822)
 // ---------------------------------------------------------------------------
@@ -361,6 +350,11 @@ pub fn serve_econ_state_query(
 // Startup helper
 // ---------------------------------------------------------------------------
 
+/// Attempt to load the economy simulation.
+///
+/// Returns `Some((EconSimResource, EconStateResource))` on success, `None` on
+/// failure (with the error logged at warn level). The server inserts these as
+/// resources when present; the economy features degrade gracefully when absent.
 pub fn try_load_economy(run_seed: u64) -> Option<(EconSimResource, EconStateResource)> {
     match Simulation::load_auto(run_seed) {
         Ok(sim) => {

server/src/simulation/input.rs

@@ -4,10 +4,10 @@
 
 use crate::bridge::debug::DebugCommandBuffer;
 use crate::bridge::types::{FacingDirection, ObjectType, PlayerAction, PlayerInput};
-use crate::simulation::economy::EconQueryBuffer;
 use crate::knowledge::{EntityRegistry, StableId};
 use crate::perception::vision_cone::{facing_from_delta, Facing};
 use crate::settings::{SettingsCommand, SettingsCommandBuffer};
+use crate::simulation::economy::EconQueryBuffer;
 use crate::simulation::interaction::{DoorInteractRequest, DoorState, TerminalInteractRequest};
 use crate::simulation::inventory::{
     find_next_slot, occupied_slots_for, CarriedBy, InventorySlot, ItemName, MAX_INVENTORY_SLOTS,
@@ -129,7 +129,7 @@ pub fn process_player_input(
                     | PlayerAction::ChangeSetting { .. }
                     | PlayerAction::RequestAllSettings
                     | PlayerAction::DeleteSetting { .. }
-                | PlayerAction::EconStateQuery { .. }
+                    | PlayerAction::EconStateQuery { .. }
             )
         {
             continue;

server/src/simulation/mod.rs

@@ -170,8 +170,7 @@ impl Plugin for SimulationPlugin {
         // Economy simulation (#821, D-031) — loaded once at startup, no-op when DB absent.
         // Uses seed 0 for now; will be threaded through StartupMessage world seed (#TODO).
         if let Some((econ_sim, econ_state)) = economy::try_load_economy(0) {
-            app.insert_resource(econ_sim)
-                .insert_resource(econ_state);
+            app.insert_resource(econ_sim).insert_resource(econ_state);
         }
         // EconQueryBuffer: always registered so EconStateQuery PlayerActions are accepted
         // even when the economy DB is absent (queries just produce no response).