allozaur/feat/chat slash commands (#26716)

* base : slash-command/misc foundation - model icon and focus-selector constants

* feat : slash-command picker and command parsing helpers

* refactor : wire command and @-mention pickers into the chat form

* ui : improve model selector keyboard navigation and load/dismiss

* feat: Unify markdown/raw-text rendering under one setting with migration

* fix: Misc fixes - tool-call subtitle, assistant wrap, progress guards

* feat: Clamp and style numeric settings inputs from registry bounds

tools/ui/src/lib/utils/index.ts

@@ -198,6 +198,13 @@ export {
 	type MentionDismissSnapshot
 } from './mention-token';
 
+// Slash-command token detection (for the `/`-triggered command picker)
+export {
+	findCommandToken,
+	takeCommandDismissSnapshot,
+	type CommandDismissSnapshot
+} from './command-token';
+
 // Mention-chip visual contract shared by the rehype file-badge plugin,
 // plus the `[name](file://...)` link helpers the mention picker splices in
 export {