feat(settings): data-safe editors, deep-linked search, Data/About/Cost pages

- EditorModal loads once per path (a parent re-render no longer reloads the
  file over the user's typing), refuses Save after a failed load, opens a
  truncated (>256 KB) file read-only, and asks before overwriting a file
  that changed on disk or could not be re-read.
- Settings/Hooks editors unset only keys from the snapshot taken at Edit,
  warn when the file changed underneath, keep a renamed key's value, and
  refuse a new key named like a redacted one (env) or a read-only hook
  event, which used to replace the secret/hooks.
- Project scope shows its resolved folder and is disabled inside the
  plugin cache. Account-profile, pricing-row and pet deletes confirm;
  two-click actions disarm after 3 s; unsaved drafts ask before closing.
- Search indexes every Claude Code / Codex sub-tab, opens it via ?tab= and
  scrolls to + highlights the row; the active config tab is in the URL.
- General splits into General / Data / About; Pricing moves to a Cost
  group with one shared load; config tabs group as Content / Extensions /
  Config with arrow-key roving; Promise.allSettled per tab.
- Data: browser-preferences export/import (allowlisted keys), per-section
  reset, housekeeping dry-run first, clear-all behind a typed phrase.
  Server: purge days must be a whole number >= 1 (INVALID_PURGE_DAYS) and
  dry_run returns exactly what the real run would delete.
- Alerts can be edited; webhooks/alerts/remote-source failures toast;
  copies go through copyText; modals get dialog roles and useDialog.
- Sagi: Ctrl/Cmd+B only when shown and not typing, default spot clear of
  row controls, arrow keys move it, reduced motion honoured; the dead
  /run launch link goes to the workspace.

client/src/pages/AiToolConfig.tsx

@@ -7,7 +7,10 @@
  * default model (`PUT /api/ai-tools/:id {defaultModel}`) for a tool with a
  * model flag; its vendor's pricing table; and the config files its catalog
  * file lists, each opened over a sha and saved by the server only if it is
- * still that sha, valid, and backed up. Antigravity adds its hooks card.
+ * still that sha, valid, and backed up — a refusal because the file changed
+ * (ESTALE) offers a reload and keeps the user's text to copy, and an edited
+ * file asks before another file or Close drops it. Antigravity adds its hooks
+ * card.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 
@@ -16,6 +19,10 @@ import { Link } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 import { Cpu, ExternalLink, FileCog, RefreshCw } from "lucide-react";
 import { api, type AiToolConfigFile } from "../lib/api";
+import { toast } from "../lib/toast";
+import { confirmDiscard } from "../lib/confirm";
+import { copyText } from "../lib/clipboard";
+import { useUnsavedGuard } from "../hooks/useUnsavedGuard";
 import type { Lane } from "../lib/types";
 import { useAiTools } from "../hooks/useAiTools";
 import { AiToolIcon } from "../components/AiToolIcon";
@@ -39,6 +46,7 @@ function DefaultModel({ toolId, saved }: { toolId: string; saved: string }) {
     setError(null);
     try {
       await aiTools.update(toolId, { defaultModel: value || null });
+      toast.success(t("toolTab.defaultModelSaved"));
     } catch (err) {
       setError(message(err));
     }
@@ -70,8 +78,14 @@ function ConfigFiles({ toolId }: { toolId: string }) {
   const [files, setFiles] = useState<AiToolConfigFile[] | null>(null);
   const [open, setOpen] = useState<{ index: number; path: string; sha: string } | null>(null);
   const [text, setText] = useState("");
+  // The text as opened/saved: an edit differs from it.
+  const [base, setBase] = useState("");
   const [busy, setBusy] = useState(false);
   const [note, setNote] = useState<{ ok: boolean; text: string } | null>(null);
+  // Set when a save was refused because the file changed on disk.
+  const [stale, setStale] = useState(false);
+  const dirty = open !== null && text !== base;
+  useUnsavedGuard(dirty);
 
   useEffect(() => {
     api.aiTools
@@ -80,26 +94,42 @@ function ConfigFiles({ toolId }: { toolId: string }) {
       .catch((err) => setNote({ ok: false, text: message(err) }));
   }, [toolId]);
 
-  const openFile = async (f: AiToolConfigFile) => {
+  const load = async (index: number) => {
     setNote(null);
+    setStale(false);
     try {
-      const r = await api.aiTools.readConfig(toolId, f.index);
-      setOpen({ index: f.index, path: r.path, sha: r.sha });
+      const r = await api.aiTools.readConfig(toolId, index);
+      setOpen({ index, path: r.path, sha: r.sha });
       setText(r.text);
+      setBase(r.text);
     } catch (err) {
       setNote({ ok: false, text: message(err) });
     }
   };
 
+  const openFile = async (f: AiToolConfigFile) => {
+    if (dirty && !(await confirmDiscard())) return;
+    await load(f.index);
+  };
+
+  const close = async () => {
+    if (dirty && !(await confirmDiscard())) return;
+    setOpen(null);
+    setStale(false);
+  };
+
   const save = async () => {
     if (!open) return;
     setBusy(true);
     setNote(null);
+    setStale(false);
     try {
       const r = await api.aiTools.saveConfig(toolId, open.index, text, open.sha);
       setOpen({ ...open, sha: r.sha });
+      setBase(text);
       setNote({ ok: true, text: t("toolTab.saved", { backup: r.backup }) });
     } catch (err) {
+      setStale((err as { code?: string }).code === "ESTALE");
       setNote({ ok: false, text: message(err) });
     } finally {
       setBusy(false);
@@ -141,16 +171,38 @@ function ConfigFiles({ toolId }: { toolId: string }) {
             <button
               type="button"
               onClick={save}
-              disabled={busy}
+              disabled={busy || !dirty}
               className="btn-ghost text-xs disabled:opacity-50"
             >
               {busy && <RefreshCw className="h-3.5 w-3.5 animate-spin" />}
               {t("toolTab.save")}
             </button>
-            <button type="button" onClick={() => setOpen(null)} className="btn-ghost text-xs">
+            <button type="button" onClick={() => void close()} className="btn-ghost text-xs">
               {t("toolTab.close")}
             </button>
           </div>
+          {stale && (
+            <div
+              role="alert"
+              className="flex flex-wrap items-center gap-2 rounded-md border border-status-warning/40 bg-status-warning/10 px-3 py-2 text-xs text-fg-primary"
+            >
+              <span className="flex-1">{t("toolTab.staleBody")}</span>
+              <button
+                type="button"
+                onClick={() => void copyText(text)}
+                className="btn-ghost text-xs"
+              >
+                {t("toolTab.copyMine")}
+              </button>
+              <button
+                type="button"
+                onClick={() => void load(open.index)}
+                className="btn-ghost text-xs"
+              >
+                {t("toolTab.reloadDiscard")}
+              </button>
+            </div>
+          )}
         </div>
       )}
       {note && (