refactor(agent): runAgent uses Agent upstreams only; deprecate legacy settings.pi fields

pi.provider / baseUrl / model / thinkingLevel / apiKeySecretRef are now
DEPRECATED_SETTINGS_FIELDS: kept in the schema for stored JSON, dropped
from PATCH /settings and from the settings sections, never read by the
server. runAgent fails with a clear message when no upstream is set.
The agent demo gate checks the default upstream provider; e2e seeds a
fake upstream as default. OpenAPI summaries say Agent upstream.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/contracts/test/pi.test.ts

@@ -58,13 +58,19 @@ describe("OAuth 请求", () => {
 });
 
 describe("settings.pi 兼容", () => {
-  it("缺省 defaultUpstreamId = null;旧字段仍可读写;PATCH 不能直接改 defaultUpstreamId", () => {
+  it("缺省 defaultUpstreamId = null;PATCH 不能直接改 defaultUpstreamId,旧字段被丢弃", () => {
     expect(C.DEFAULT_SETTINGS.pi.defaultUpstreamId).toBeNull();
     expect(C.GlobalSettings.safeParse(C.DEFAULT_SETTINGS).success).toBe(true);
     const patch = C.GlobalSettingsUpdate.parse({
-      pi: { defaultUpstreamId: "7d3f7f5e-8a8c-4b8e-9f0a-1b2c3d4e5f60", provider: "fake", contextBudget: 64_000 },
+      pi: {
+        defaultUpstreamId: "7d3f7f5e-8a8c-4b8e-9f0a-1b2c3d4e5f60",
+        provider: "fake",
+        apiKey: "sk-x",
+        model: "m",
+        contextBudget: 64_000,
+      },
     });
-    expect(patch.pi).toEqual({ provider: "fake", contextBudget: 64_000 });
+    expect(patch.pi).toEqual({ contextBudget: 64_000 });
     const current = { ...C.DEFAULT_SETTINGS, pi: { ...C.DEFAULT_SETTINGS.pi, defaultUpstreamId: "keep-me" } };
     expect(C.mergeSettings(current as never, patch).pi.defaultUpstreamId).toBe("keep-me");
   });

packages/contracts/test/schemas.test.ts

@@ -157,11 +157,11 @@ describe("关键合同行为", () => {
   });
 
   it("GlobalSettingsUpdate 部分更新不会注入默认值,mergeSettings 保留现值", () => {
-    const patch = C.GlobalSettingsUpdate.parse({ automation: { enabled: false }, pi: { apiKey: "sk-x" } });
-    expect(patch).toEqual({ automation: { enabled: false }, pi: { apiKey: "sk-x" } });
+    const patch = C.GlobalSettingsUpdate.parse({ automation: { enabled: false }, pi: { contextBudget: 64_000 } });
+    expect(patch).toEqual({ automation: { enabled: false }, pi: { contextBudget: 64_000 } });
     const merged = C.mergeSettings(C.DEFAULT_SETTINGS, patch);
     expect(merged.automation).toEqual({ enabled: false, readOnlyReconcile: false });
-    expect(merged.pi).toEqual(C.DEFAULT_SETTINGS.pi);
+    expect(merged.pi).toEqual({ ...C.DEFAULT_SETTINGS.pi, contextBudget: 64_000 });
     expect(C.GlobalSettings.safeParse(merged).success).toBe(true);
   });
 

packages/contracts/test/settings-sections.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
 import {
   DEFAULT_SETTINGS,
+  DEPRECATED_SETTINGS_FIELDS,
   SETTINGS_SECTIONS,
   SettingsSectionId,
   settingsSectionForLegacyTab,
@@ -11,8 +12,11 @@ describe("SETTINGS_SECTIONS", () => {
     expect(SETTINGS_SECTIONS.map((s) => s.id)).toEqual(SettingsSectionId.options);
   });
 
-  it("8 个存储 key 的每个字段恰好归属一个分区", () => {
-    const all = Object.entries(DEFAULT_SETTINGS).flatMap(([key, v]) => Object.keys(v).map((f) => `${key}.${f}`));
+  it("8 个存储 key 的每个字段(弃用字段除外)恰好归属一个分区", () => {
+    const deprecated = new Set<string>(DEPRECATED_SETTINGS_FIELDS);
+    const all = Object.entries(DEFAULT_SETTINGS)
+      .flatMap(([key, v]) => Object.keys(v).map((f) => `${key}.${f}`))
+      .filter((f) => !deprecated.has(f));
     const owned = SETTINGS_SECTIONS.flatMap((s) => s.fields);
     expect(new Set(owned).size).toBe(owned.length);
     expect([...owned].sort()).toEqual([...all].sort());