feat: WebUI 改为依赖 /api/v1，UI 与 agent 共用一套 API 契约

- sources / sort / keys 三个页面的数据源从 /api/sources 切到 /api/v1/sources
  （写操作仍走 /api/sources：v1 是只读门面，不做变更）
- 编辑弹窗改用 /api/v1/sources/{name}?reveal=credentials（admin-only）取明文 key。
  这是必须的：表单要整体回传源，若不回填 key，改个端口就会把 key 清空。
- 遮蔽视图仍是默认，只有显式 reveal 才返回明文

端到端验证（真浏览器 + 临时实例，非仅 API 测试）：
- sources/sort/keys 三页实际发出 GET /api/v1/sources，0 console error
- editSource('demo') → reveal=credentials，#s-key 与 #s-url 正确回填
- 写入往返：改 base_url /v1→/v2 后重开，key 仍在（未被清空）
- 落盘 api_key 明文残留 0、密文 1

测试：+1（reveal 必须 admin，否则任意 user key 可读全部凭据）
变异验证：reveal 去掉 admin 校验 → 403 断言变红

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/gateway/apiv1.go

@@ -68,6 +68,19 @@ func (g *Gateway) apiV1Routes(w http.ResponseWriter, r *http.Request) {
 		}
 		for _, s := range g.core.Sources() {
 			if s.Name == name {
+				// ?reveal=credentials is admin-only and is what the Web UI's
+				// edit dialog uses: a form that round-trips a source must be
+				// able to show the current key, otherwise saving an unrelated
+				// field would blank it. Everything else stays masked.
+				if r.URL.Query().Get("reveal") == "credentials" {
+					if reqRole(r.Context()) != "admin" {
+						writeError(w, http.StatusForbidden, "forbidden",
+							"admin role required to reveal credentials")
+						return
+					}
+					writeJSON(w, http.StatusOK, map[string]interface{}{"source": s})
+					return
+				}
 				writeJSON(w, http.StatusOK, map[string]interface{}{"source": maskSource(s)})
 				return
 			}
@@ -176,6 +189,9 @@ func (g *Gateway) apiV1Index(w http.ResponseWriter, r *http.Request) {
 			"path_escape":  "URL-encode source and key names; {name} is a single path segment",
 			"idempotency":  "POST /api/sources and PUT /api/sources/{name} both upsert by name",
 			"config_truth": "all configuration lives in config.yaml; API writes are persisted immediately",
+			"credentials": "credentials are masked by default. GET /api/v1/sources/{name}?reveal=credentials " +
+				"returns them in the clear and is admin-only — the Web UI edit dialog uses it, because a form " +
+				"that round-trips a source must show the current key or saving another field would blank it.",
 		},
 	}
 	writeJSON(w, http.StatusOK, index)

internal/gateway/apiv1_test.go

@@ -271,3 +271,29 @@ func serveViaHandler(t *testing.T, g *Gateway, req *http.Request) *httptest.Resp
 	g.Handler().ServeHTTP(rec, req)
 	return rec
 }
+
+// TestAPIV1RevealRequiresAdmin: the only way to read a key in the clear is the
+// explicit admin-only reveal. Without the role check this endpoint would hand
+// every source credential to any valid (even user-scoped) key.
+func TestAPIV1RevealRequiresAdmin(t *testing.T) {
+	g, _, user := v1Gateway(t)
+	rec := serveViaHandler(t, g, newAuthedRequest(t, http.MethodGet, "/api/v1/sources/up?reveal=credentials", user))
+	if rec.Code != http.StatusForbidden {
+		t.Errorf("user reveal = %d, want 403: %s", rec.Code, rec.Body.String())
+	}
+	if strings.Contains(rec.Body.String(), "sk-up-secret") {
+		t.Error("a forbidden reveal still leaked the key")
+	}
+	rec = doReq(t, g, http.MethodGet, "/api/v1/sources/up?reveal=credentials", "")
+	if rec.Code != http.StatusOK {
+		t.Fatalf("admin reveal = %d: %s", rec.Code, rec.Body.String())
+	}
+	if !strings.Contains(rec.Body.String(), "sk-up-secret") {
+		t.Error("admin reveal should return the key in the clear (the edit form needs it)")
+	}
+	// The masked default view must still hide it on the same path.
+	rec = doReq(t, g, http.MethodGet, "/api/v1/sources/up", "")
+	if strings.Contains(rec.Body.String(), "sk-up-secret") {
+		t.Error("the default view leaked the key")
+	}
+}

internal/gateway/ui/index.html

@@ -2772,7 +2772,10 @@
 
       /* ---------- sources tab ---------- */
       async function renderSources() {
-        const j = await api("/api/sources");
+        // Read through /api/v1: the UI is a client of the same public API an
+        // agent uses, so there is one contract rather than a private path.
+        // The list view needs no credentials, so the masked view is enough.
+        const j = await api("/api/v1/sources");
         const rows = j.sources
           .map(
             (
@@ -2794,13 +2797,23 @@
       function editSource(name) {
         const wrap = document.createElement("div");
         wrap.id = "modal-wrap";
-        Promise.all([api("/api/sources"), api("/api/status")])
-          .then(([src, st]) => {
-            const s = src.sources.find((x) => x.name === name) || {
-              name: name,
-              models: [{ id: "", priority: 0, kind: "chat" }],
-            };
-            const cur = s.adapter || "openai";
+            // The edit dialog round-trips the whole source, so it must load the
+            // real api_key — otherwise saving an unrelated field would blank
+            // it. That is what ?reveal=credentials is for (admin-only).
+            const srcPath = name
+              ? "/api/v1/sources/" + encodeURIComponent(name) + "?reveal=credentials"
+              : "/api/v1/sources";
+            Promise.all([api(srcPath), api("/api/status")])
+              .then(([src, st]) => {
+                // Editing: the single-source shape. Creating: an empty form.
+                const s = name
+                  ? src.source
+                  : { name: "", models: [{ id: "", priority: 0, kind: "chat" }] };
+                if (!s) {
+                  toast(t("toastSave"));
+                  return;
+                }
+                const cur = s.adapter || "openai";
             const apps = ["", ...(st.adapters || []).map((a) => a.name)];
             if (cur && !apps.includes(cur)) apps.push(cur);
             const adSel =
@@ -3215,7 +3228,7 @@
       const sortLanes = { chat: [], image: [] };
       let sortStateMap = new Map();
       async function renderSort() {
-        const j = await api("/api/sources");
+        const j = await api("/api/v1/sources");
         let autoR = [];
         let autoImg = [];
         try {
@@ -4155,7 +4168,7 @@
       async function loadModelPairs() {
         let srcs = [];
         try {
-          srcs = (await api("/api/sources")).sources || [];
+          srcs = (await api("/api/v1/sources")).sources || [];
         } catch (e) {}
         const pairs = [];
         (srcs || []).forEach((s) =>