feat(oidc): add fine grained access control (#91)

* feat(access-control): fine grain tokens

* fix(docs): clean wording

* test(access-control): add tests for team extraction from access tokens and bucket info permissions

* test(vocabulary): add test for ExpandGlob function to reject non-glob patterns

* feat(helm): add multi-user access control documentation and schema support

frontend/src/hooks/index.ts

@@ -1,2 +1,3 @@
 export { useDashboardData, useBuckets } from './useApi';
 export { useBucketObjects } from './useBucketObjects';
+export { usePermissions, bucketCan, useBucketCan } from './usePermissions';

frontend/src/hooks/usePermissions.ts

@@ -0,0 +1,76 @@
+import { useCapabilities } from './useCapabilities';
+
+/**
+ * Permission view derived from /api/v1/capabilities.
+ *
+ * Fail-closed: while capabilities are loading (or errored), every check
+ * returns false. Gated UI stays hidden until the server has spoken.
+ * When access control is disabled server-side, every check returns true.
+ */
+export function usePermissions() {
+  const { data, isLoading, isError } = useCapabilities();
+  const ac = data?.access_control;
+  const settled = !isLoading && !isError && data !== undefined;
+  const enabled = ac?.enabled ?? false;
+  const isAdmin = settled && (!enabled || (ac?.is_admin ?? false));
+  const bindings = ac?.bindings ?? [];
+  const clusterPerms = ac?.cluster_permissions ?? [];
+
+  const hasClusterPerm = (perm: string): boolean => {
+    if (!settled) return false;
+    if (!enabled || isAdmin) return true;
+    return clusterPerms.includes(perm);
+  };
+
+  const hasAnyPerm = (perm: string): boolean => {
+    if (!settled) return false;
+    if (!enabled || isAdmin) return true;
+    return bindings.some((b) => b.permissions.includes(perm));
+  };
+
+  const hasAnyClusterAccess =
+    settled &&
+    (!enabled || isAdmin || clusterPerms.some((p) => p.startsWith('cluster.') || p.startsWith('node.')));
+
+  const noAccess =
+    settled && enabled && !isAdmin && bindings.length === 0 && clusterPerms.length === 0;
+
+  return { loading: !settled, enabled, isAdmin, hasClusterPerm, hasAnyPerm, hasAnyClusterAccess, noAccess };
+}
+
+/**
+ * Per-bucket check against the server-computed effective_permissions carried
+ * on bucket payloads. Does not know about loading/enabled state, so it treats
+ * a missing effective_permissions field as "access control is disabled" and
+ * allows. That's only correct when access control really is disabled, so
+ * this is kept for internal use (by useBucketCan below); UI code should call
+ * useBucketCan() instead, which fails closed when access control is enabled.
+ */
+export function bucketCan(
+  bucket: { effective_permissions?: string[] } | undefined,
+  perm: string,
+): boolean {
+  const perms = bucket?.effective_permissions;
+  if (!perms) return true;
+  return perms.includes(perm);
+}
+
+/**
+ * Hook returning a per-bucket permission check closed over the current
+ * loading/enabled state from usePermissions().
+ *
+ * Fail-closed: while capabilities are loading, every check denies. When
+ * access control is enabled, a bucket without effective_permissions (not
+ * loaded yet, or filtered out of the bucket list) also denies instead of
+ * falling open like bucketCan does. When access control is disabled, every
+ * check allows, same as bucketCan.
+ */
+export function useBucketCan() {
+  const { loading, enabled } = usePermissions();
+  return (bucket: { effective_permissions?: string[] } | undefined, perm: string): boolean => {
+    if (loading) return false;
+    if (!enabled) return true;
+    if (!bucket?.effective_permissions) return false;
+    return bucketCan(bucket, perm);
+  };
+}