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/constants/chat-commands.ts

@@ -0,0 +1,44 @@
+import { SET_WORKING_DIRECTORY_LABEL } from '$lib/constants/working-directory';
+import { ChatFormCommandAction } from '$lib/enums';
+import type { ChatFormCommand } from '$lib/types';
+
+interface ChatCommandsOptions {
+	/** Gates `/model`. */
+	showModelSelector: boolean;
+	/** Gates `/prompt`. */
+	hasPrompts: () => boolean;
+	/** Gates `/cwd`. */
+	hasBuiltinTools: () => boolean;
+}
+
+/**
+ * The slash commands surfaced by the `/` command picker, in display order.
+ *
+ * Availability is supplied as predicates rather than store imports: this
+ * module is re-exported through the `$lib/constants` barrel, and importing
+ * stores at module load would create a circular dependency (the stores
+ * themselves import from `$lib/constants`).
+ */
+export function getChatCommands(options: ChatCommandsOptions): ChatFormCommand[] {
+	return [
+		{
+			name: 'prompt',
+			description: 'Insert an MCP prompt',
+			action: ChatFormCommandAction.PROMPT,
+			disabled: !options.hasPrompts()
+		},
+		{
+			name: 'cwd',
+			description: SET_WORKING_DIRECTORY_LABEL,
+			keywords: ['current working directory'],
+			action: ChatFormCommandAction.CWD,
+			disabled: !options.hasBuiltinTools()
+		},
+		{
+			name: 'model',
+			description: 'Select model',
+			action: ChatFormCommandAction.MODEL,
+			disabled: !options.showModelSelector
+		}
+	];
+}