ui: move get_datetime tool to frontend (#27255)

* ui: move get_datetime tool to frontend

* clarify docs

* server: drop the now unused ctime include

strftime() and gmtime_r() were the only users, both went away with the
get_datetime tool. Also make the renderer's catch inert: the browser
executor always emits JSON, so a non-JSON result is no longer a date to
display.

---------

Co-authored-by: Pascal <admin@serveurperso.com>

tools/ui/src/lib/constants/built-in-tools.constants.ts

@@ -34,7 +34,7 @@ export const BUILTIN_TOOL_UI: Readonly<Record<BuiltInTool, BuiltinToolUiEntry>>
 		label: 'Search files',
 		source: ToolSource.BUILTIN
 	},
-	[BuiltInTool.GET_DATETIME]: { icon: Clock, label: 'Current time', source: ToolSource.BUILTIN },
+	[BuiltInTool.GET_DATETIME]: { icon: Clock, label: 'Current time', source: ToolSource.FRONTEND },
 	[BuiltInTool.GET_INFO]: { icon: Info, label: 'Runtime info', source: ToolSource.BUILTIN },
 	[BuiltInTool.GREP_SEARCH]: {
 		icon: SearchCode,

tools/ui/src/lib/constants/get-datetime.ts

@@ -0,0 +1,20 @@
+import { BuiltInTool, JsonSchemaType, ToolCallType } from '$lib/enums';
+import type { OpenAIToolDefinition } from '$lib/types';
+
+export const GET_DATETIME_TOOL_NAME = BuiltInTool.GET_DATETIME;
+
+export function buildGetDatetimeToolDefinition(): OpenAIToolDefinition {
+	return {
+		function: {
+			description:
+				'Returns the current local date and time in ISO 8601 format, with the IANA time zone name',
+			name: GET_DATETIME_TOOL_NAME,
+			parameters: {
+				properties: {},
+				required: [],
+				type: JsonSchemaType.OBJECT
+			}
+		},
+		type: ToolCallType.FUNCTION
+	};
+}

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

@@ -59,4 +59,5 @@ export * from './uri-template.constants';
 export * from './url.constants';
 export * from './working-directory.constants';
 export * from './read-media';
+export * from './get-datetime';
 export * from './browser-info';