refactor(simulation): split the input.rs and dialogue.rs dispatchers (T-1062)

input.rs 2,739 → 858 lines: per-domain action handlers moved to their
owning modules (inventory, movement, stance, examine, follow, interaction,
save_io, settings, bridge::debug, economy, vision_cone, bookmark,
test_world reset + new teleport.rs); input.rs keeps the queue, the thin
dispatch table, and pause/cooldown glue. All 9 type_complexity allows
dissolved via one PlayerInputQuery alias.

dialogue.rs → dialogue/ directory module: selection (631), response
(1,473), confrontation (714), mod.rs (226, shared session components +
re-exports — public paths preserved). Documented seam deviation:
process_walk_away lives with confrontation (D-064/D-063 share the same
world-response shape).

Mechanical, zero behavior change: determinism + golden_suite byte-identical
(independently re-verified); 1,504 lib tests unchanged — 23 input tests
moved with their subjects, 53 dialogue tests redistributed, zero deleted.
System scheduling registrations untouched (input_plugin.rs 0-line diff).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

server/src/simulation/stance.rs

@@ -96,6 +96,30 @@ impl PlayerMoveCooldown {
     }
 }
 
+/// Step the player's stance one level up or down the ladder (D-053).
+/// No-op when the player has no Stance component or is already at the end.
+pub fn handle_toggle_stance(
+    player_query: &mut crate::simulation::input::PlayerInputQuery,
+    up: bool,
+) {
+    if let Ok((_, _, Some(mut stance), _)) = player_query.single_mut() {
+        let new_stance = if up {
+            stance.0.step_up()
+        } else {
+            stance.0.step_down()
+        };
+        if new_stance != stance.0 {
+            tracing::debug!(
+                "Stance {}: {:?} -> {:?}",
+                if up { "up" } else { "down" },
+                stance.0,
+                new_stance
+            );
+            stance.0 = new_stance;
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -253,4 +277,69 @@ mod tests {
         let stance = world.get::<Stance>(entity).unwrap();
         assert_eq!(stance.0, MovementStance::Walk);
     }
+
+    // -----------------------------------------------------------------------
+    // handle_toggle_stance ladder tests (moved from input.rs, T-1062)
+    // -----------------------------------------------------------------------
+
+    use crate::bridge::types::{PlayerAction, PlayerInput};
+    use crate::simulation::input::{process_player_input, InputQueue};
+    use crate::simulation::movement::{PlayerCharacter, TilePosition};
+    use crate::simulation::time::SimulationTime;
+
+    #[test]
+    fn toggle_stance_up_changes_stance() {
+        let mut world = bevy_ecs::world::World::new();
+        world.insert_resource(InputQueue::default());
+        world.insert_resource(SimulationTime::default());
+        world.init_resource::<crate::knowledge::EntityRegistry>();
+
+        world.spawn((
+            PlayerCharacter,
+            TilePosition::new(5, 5, 0),
+            Stance::default(),
+            PlayerMoveCooldown::default(),
+        ));
+
+        world.resource_mut::<InputQueue>().push(PlayerInput {
+            tick: 0,
+            action: PlayerAction::ToggleStanceUp,
+        });
+
+        let mut schedule = bevy_ecs::schedule::Schedule::default();
+        schedule.add_systems(process_player_input);
+        schedule.run(&mut world);
+
+        let mut query = world.query::<&Stance>();
+        let stance = query.single(&world).unwrap();
+        assert_eq!(stance.0, MovementStance::Sprint);
+    }
+
+    #[test]
+    fn toggle_stance_down_changes_stance() {
+        let mut world = bevy_ecs::world::World::new();
+        world.insert_resource(InputQueue::default());
+        world.insert_resource(SimulationTime::default());
+        world.init_resource::<crate::knowledge::EntityRegistry>();
+
+        world.spawn((
+            PlayerCharacter,
+            TilePosition::new(5, 5, 0),
+            Stance::default(),
+            PlayerMoveCooldown::default(),
+        ));
+
+        world.resource_mut::<InputQueue>().push(PlayerInput {
+            tick: 0,
+            action: PlayerAction::ToggleStanceDown,
+        });
+
+        let mut schedule = bevy_ecs::schedule::Schedule::default();
+        schedule.add_systems(process_player_input);
+        schedule.run(&mut world);
+
+        let mut query = world.query::<&Stance>();
+        let stance = query.single(&world).unwrap();
+        assert_eq!(stance.0, MovementStance::Careful);
+    }
 }