fix(dashboard): redirect after a member removes themselves

A member-with-app_admin who removes their own membership keeps a now-
broken Members tab open until reload — `myRole` is only computed once
in `loadApp`, and the next `/apps/{slug}` fetch would 403 anyway.

After the DELETE succeeds, if the removed user is the caller, navigate
back to /apps instead of refreshing the local member list.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

dashboard/src/routes/apps/[slug]/+page.svelte

@@ -16,6 +16,9 @@
 	import ConfirmModal from '$lib/ConfirmModal.svelte';
 	import ActionMenu from '$lib/ActionMenu.svelte';
 	import RoleChip from '$lib/RoleChip.svelte';
+	import { currentUser } from '$lib/auth';
+
+	const me = $derived($currentUser);
 
 	const SAMPLE_SOURCE =
 		'#{\n  statusCode: 200,\n  body: #{ ok: true, echo: ctx.request.body }\n}';
@@ -308,8 +311,16 @@
 		removingMember = true;
 		removeMemberError = null;
 		try {
+			const removedSelf = !!me && memberToRemove.user_id === me.id;
 			await api.appMembers.remove(app.id, memberToRemove.user_id);
 			memberToRemove = null;
+			if (removedSelf) {
+				// We just revoked our own access to this app; the next
+				// fetch of /apps/{slug} would 403. Bounce back to the
+				// apps list rather than render a broken tab.
+				await goto(`${base}/apps`);
+				return;
+			}
 			await loadMembers(app.id);
 		} catch (e) {
 			removeMemberError = e instanceof Error ? e.message : String(e);