feat(web): settings with 9 sidebar sections and Agent upstream management

- /console/settings#<section>[/<anchor>]; legacy ?tab= redirected in clientLoader
- SETTINGS_SECTIONS in contracts with field-ownership test
- Agent section: upstream list, create wizard (provider -> credentials/model -> login/test/default),
  edit drawer with OAuth browser/device login, test, set default, delete
- sites section with site registration, snapshot/rate-limit drawer and account credentials
- path mappings moved into downloader / media-server drawers; metadata and account sections

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

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

@@ -0,0 +1,39 @@
+import { describe, expect, it } from "vitest";
+import {
+  DEFAULT_SETTINGS,
+  SETTINGS_SECTIONS,
+  SettingsSectionId,
+  settingsSectionForLegacyTab,
+} from "../src/settings.ts";
+
+describe("SETTINGS_SECTIONS", () => {
+  it("9 个分区,顺序与 SettingsSectionId 一致", () => {
+    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}`));
+    const owned = SETTINGS_SECTIONS.flatMap((s) => s.fields);
+    expect(new Set(owned).size).toBe(owned.length);
+    expect([...owned].sort()).toEqual([...all].sort());
+  });
+
+  it("旧 ?tab= 值都能落到分区", () => {
+    for (const tab of [
+      "automation",
+      "downloaders",
+      "media-servers",
+      "library-roots",
+      "path-mappings",
+      "site-credentials",
+      "api-keys",
+      "pi",
+      "storage",
+    ]) {
+      expect(settingsSectionForLegacyTab(tab), tab).not.toBeNull();
+    }
+    expect(settingsSectionForLegacyTab("storage")).toEqual({ section: "automation", anchor: "cache" });
+    expect(settingsSectionForLegacyTab("path-mappings")).toEqual({ section: "downloaders", anchor: undefined });
+    expect(settingsSectionForLegacyTab("nope")).toBeNull();
+  });
+});