feat(hub): org-scoped agent role/skill folder tree (ADR-0028)

Add a shared transparent OrganizationAgentConfigFolder tree for grouping
agent roles and skills in the admin UI without affecting identity, bindings,
run loading, or slash commands.

hub/admin-web/src/lib/components/RoleCard.svelte

@@ -14,15 +14,20 @@
 		models,
 		skills,
 		slug,
+		folderItems,
 		onupdated,
 		onskillschanged,
+		onfolderchanged,
 	}: {
 		r: AgentRoleRow;
 		models: AgentModelRow[];
 		skills: AgentSkillRow[];
 		slug: string;
+		/** ADR-0028 folder choices ('' = 未分类); transparent grouping only */
+		folderItems: { value: string; label: string }[];
 		onupdated: (updated: AgentRoleRow) => void;
 		onskillschanged: (roleId: string, skillNames: string[]) => void;
+		onfolderchanged: (roleId: string, folderId: string | null) => void;
 	} = $props();
 
 	const initial = {
@@ -44,6 +49,8 @@
 	let isDefault = $state(initial.isDefault);
 	let selectedSkills = $state<string[]>([...initial.skillNames]);
 	let saving = $state(false);
+	let folderValue = $state(r.folderId ?? '');
+	let savingFolder = $state(false);
 
 	const groupedTools = TOOL_OPTIONS.reduce(
 		(acc, t) => {
@@ -105,6 +112,24 @@
 	function sortKeyDirty(): boolean {
 		return Number(sortOrder) !== r.sortOrder;
 	}
+
+	// ADR-0028: folder assignment is a label-class change — instant-apply, no
+	// session archival, independent of the configuration save button.
+	async function saveFolder(next: string) {
+		const folderId = next === '' ? null : next;
+		if (folderId === r.folderId) return;
+		savingFolder = true;
+		try {
+			await api.setAgentRoleFolder(slug, r.roleId, folderId);
+			onfolderchanged(r.roleId, folderId);
+			toastSuccess('已更新所属文件夹');
+		} catch (err) {
+			folderValue = r.folderId ?? '';
+			toastError(err instanceof Error ? err.message : String(err));
+		} finally {
+			savingFolder = false;
+		}
+	}
 </script>
 
 <div class="saas-card-pad">
@@ -114,6 +139,12 @@
 		{#if r.isDefault}
 			<span class="saas-badge-success">默认</span>
 		{/if}
+		<div class="ml-auto flex items-center gap-2">
+			<span class="text-xs text-surface-600">文件夹</span>
+			<div class="w-44">
+				<SelectField items={folderItems} bind:value={folderValue} disabled={savingFolder} onchange={saveFolder} />
+			</div>
+		</div>
 	</div>
 
 	<div class="grid grid-cols-1 gap-4 md:grid-cols-2">