feat: document edit inline + client dashboard sidebar layout

- actions.ts: add updateDocument server action (label + url, Zod validated)
- DocumentRow: Client Component with hover-reveal edit/remove buttons,
  inline edit form with pre-filled fields and cancel/save
- DocumentsTab: use DocumentRow, remove variant dependency
- client-dashboard: two-column layout (sidebar left on lg+):
  sidebar = payments + documents + notes (sticky top)
  main = brief + phases toggle (timeline / kanban)
  mobile: main first, sidebar below (order-1/order-2)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/admin/clients/[id]/actions.ts

@@ -117,6 +117,23 @@ export async function addDocument(clientId: string, formData: FormData) {
   revalidatePath(`/admin/clients/${clientId}`);
 }
 
+export async function updateDocument(
+  documentId: string,
+  clientId: string,
+  formData: FormData
+) {
+  const parsed = docSchema.safeParse({
+    label: formData.get("label"),
+    url: formData.get("url"),
+  });
+  if (!parsed.success) throw new Error(parsed.error.issues[0].message);
+  await db
+    .update(documents)
+    .set(parsed.data)
+    .where(eq(documents.id, documentId));
+  revalidatePath(`/admin/clients/${clientId}`);
+}
+
 export async function deleteDocument(documentId: string, clientId: string) {
   await db.delete(documents).where(eq(documents.id, documentId));
   revalidatePath(`/admin/clients/${clientId}`);