Status LEDs, image model selection, backup restore, provider test, monthly versions

- Sidebar: three status LEDs (server, models, MCP) with an overview popover (/api/status)
- Images: preview stage, purpose-based model choice and reference images
  (Nano Banana Pro edit refines the chosen preview)
- Settings: restore a stored or uploaded backup (staged, applied on restart)
- Provider form: test connection; saving or reloading re-checks the status at once
- opencode Zen/Go: send x-opencode-session with a stable id per conversation
- Releases are named vYYYYMM-NNNNN; scripts/release.sh numbers, tags, builds and publishes
- Fix: backups made in the same second no longer overwrite each other

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/components/Settings.tsx

@@ -461,6 +461,33 @@ function ProviderEditor({ name, p, reload, status }: { name: string; p: Json; re
       return savePatches(patches);
     });
 
+  // Check URL and key as entered, without saving.
+  const [testResult, setTestResult] = useState<{ ok: boolean; text: string }>();
+  const [testing, setTesting] = useState(false);
+  const test = async () => {
+    setTesting(true);
+    setTestResult(undefined);
+    try {
+      const r = await post<{ status: ProviderStatus; models: number }>("/providers/test", {
+        name,
+        kind: form.kind,
+        base_url: form.base_url,
+        api_key: form.api_key,
+        auth_prefix: form.auth_prefix ?? "",
+      });
+      const st = r.status;
+      setTestResult(
+        st.up
+          ? { ok: true, text: t("settings.testOk", { ms: st.latency_ms, n: r.models }) }
+          : { ok: false, text: `${st.state === "auth" ? t("settings.providerAuth") : t("settings.providerDown")}: ${st.error ?? ""}` },
+      );
+    } catch (e: any) {
+      setTestResult({ ok: false, text: e.message });
+    } finally {
+      setTesting(false);
+    }
+  };
+
   const remove = async () => {
     if (!(await confirmDialog({ message: t("settings.deleteProviderConfirm", { name }), danger: true, confirmLabel: t("common.delete") }))) return;
     void run(() => savePatches([{ path: ["providers", name], value: null }]));
@@ -614,7 +641,15 @@ function ProviderEditor({ name, p, reload, status }: { name: string; p: Json; re
           </div>
           {models.length === 0 && <div className="hint" style={{ color: "var(--muted)", fontSize: 12 }}>{t("settings.modelsEmptyHint")}</div>}
           {view}
+          {testResult && (
+            <div className={`notice ${testResult.ok ? "ok" : "err"}`} style={{ marginTop: 12 }}>
+              {testResult.text}
+            </div>
+          )}
           <div className="row" style={{ marginTop: 12 }}>
+            <button onClick={test} disabled={testing || !form.base_url}>
+              <Icon name="plug" /> {testing ? t("settings.testing") : t("settings.testConnection")}
+            </button>
             <button className="primary" onClick={save}>
               {t("common.save")}
             </button>
@@ -637,9 +672,10 @@ function Providers({ cfg, reload }: { cfg: ConfigResponse; reload: () => void })
   const providers = cfg.config.providers ?? {};
   const [status, setStatus] = useState<Record<string, ProviderStatus>>({});
   const [checking, setChecking] = useState(false);
+  // Saving a provider re-checks it on the server, so refresh whenever the config changes.
   useEffect(() => {
     get<Record<string, ProviderStatus>>("/providers/status").then(setStatus).catch(() => {});
-  }, []);
+  }, [cfg]);
   const recheck = () => {
     setChecking(true);
     post<Record<string, ProviderStatus>>("/providers/status")