feat(web,core): enterprise-managed authorization (EMA) (#1509) (#1512)

Adds enterprise-managed authorization (EMA): browser-side IdP login + RFC 8693 token-exchange and JWT-bearer resource-token mint, per-server EMA opt-in in Server Settings, IdP config in Client Settings, and IdP clientSecret keychain storage. Includes the v2/main merge and review follow-ups (400 on malformed client config; normalizeIdpIssuer import consolidation).

core/react/useClientSettingsDraft.ts

@@ -0,0 +1,93 @@
+/**
+ * Draft state for the install-level client settings modal (client.json).
+ *
+ * Same controlled-modal pattern as {@link useSettingsDraft}: local draft,
+ * debounced persist, synchronous `flush` on close. Keyed on modal
+ * open/close (`opened`) rather than a server id because client config is
+ * install-level, not per-server.
+ */
+import { useCallback, useEffect, useRef, useState } from "react";
+
+export interface UseClientSettingsDraftOptions<T> {
+  opened: boolean;
+  resolveInitial: () => T;
+  onPersist: (value: T) => Promise<void>;
+  onError: (err: unknown) => void;
+  debounceMs?: number;
+}
+
+export interface UseClientSettingsDraftResult<T> {
+  draft: T | null;
+  onChange: (next: T) => void;
+  flush: () => void;
+}
+
+export function useClientSettingsDraft<T>({
+  opened,
+  resolveInitial,
+  onPersist,
+  onError,
+  debounceMs = 300,
+}: UseClientSettingsDraftOptions<T>): UseClientSettingsDraftResult<T> {
+  const [draft, setDraft] = useState<T | null>(null);
+  const timerRef = useRef<ReturnType<typeof setTimeout> | undefined>(undefined);
+
+  const resolveInitialRef = useRef(resolveInitial);
+  const onPersistRef = useRef(onPersist);
+  const onErrorRef = useRef(onError);
+  const draftRef = useRef<T | null>(null);
+  const openedRef = useRef(opened);
+  resolveInitialRef.current = resolveInitial;
+  onPersistRef.current = onPersist;
+  onErrorRef.current = onError;
+  draftRef.current = draft;
+  openedRef.current = opened;
+
+  useEffect(() => {
+    if (!opened) {
+      setDraft(null);
+      return;
+    }
+    setDraft(resolveInitialRef.current());
+  }, [opened]);
+
+  useEffect(() => {
+    return () => {
+      if (timerRef.current) {
+        clearTimeout(timerRef.current);
+        timerRef.current = undefined;
+      }
+    };
+  }, []);
+
+  const persist = useCallback((value: T) => {
+    onPersistRef.current(value).catch((err) => {
+      onErrorRef.current(err);
+    });
+  }, []);
+
+  const onChange = useCallback(
+    (next: T) => {
+      if (!opened) return;
+      setDraft(next);
+      if (timerRef.current) clearTimeout(timerRef.current);
+      timerRef.current = setTimeout(() => {
+        timerRef.current = undefined;
+        persist(next);
+      }, debounceMs);
+    },
+    [opened, debounceMs, persist],
+  );
+
+  const flush = useCallback(() => {
+    if (!timerRef.current) return;
+    clearTimeout(timerRef.current);
+    timerRef.current = undefined;
+    const value = draftRef.current;
+    if (openedRef.current && value !== null) {
+      persist(value);
+    }
+  }, [persist]);
+
+  return { draft, onChange, flush };
+}