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/settings/mod.rs

@@ -120,6 +120,25 @@ pub enum SettingsCommand {
     Delete { key: String },
 }
 
+/// Queue a settings command from player input.
+/// `None` means the buffer was never registered (warn and drop).
+pub fn queue_settings_command(buf: Option<&mut SettingsCommandBuffer>, cmd: SettingsCommand) {
+    let label = match cmd {
+        SettingsCommand::Change { .. } => "ChangeSetting",
+        SettingsCommand::RequestAll => "RequestAllSettings",
+        SettingsCommand::Delete { .. } => "DeleteSetting",
+    };
+    match buf {
+        Some(buf) => buf.push(cmd),
+        None => {
+            tracing::warn!(
+                "{} received but SettingsCommandBuffer not registered",
+                label
+            );
+        }
+    }
+}
+
 /// Process settings commands from the IPC buffer.
 /// Reads SettingsCommandBuffer, writes to SettingsStoreResource,
 /// and stages a response in SnapshotBuffer.pending_settings_response.