Initialize repository with harness code and assets

Initial import of all source code, config, and README assets: the
packages workspace (cli, core, server, web, docs, landing, skills),
build scripts, tooling config, and CI workflows.

Includes the data-layout revision made on this branch: the local data
root defaults to ~/.penguin/data (PENGUIN_HOME still overrides; the
installer keeps its binaries in ~/.penguin), and every Agent lives
under <project>/agents/<agent>/ — path helpers, the three
agent-enumeration scans, the system prompt, built-in Skills, tests
and docs all follow the new layout.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018ihk8iQuo3kv2aPjAYEPuR

packages/web/test/locale.test.ts

@@ -0,0 +1,20 @@
+/**
+ * locale.tsx unit tests: device language resolution (language follows
+ * navigator.language when no stored preference exists; language/theme
+ * initialization does not depend on login state and also applies on the
+ * login page).
+ */
+import { describe, expect, it } from "vitest";
+import { resolveSystemLocale } from "../src/state/locale";
+
+describe("resolveSystemLocale（navigator.language → 界面语言）", () => {
+  it("zh 前缀（任意大小写与地区变体）→ zh", () => {
+    expect(resolveSystemLocale("zh-CN")).toBe("zh");
+    expect(resolveSystemLocale("ZH-TW")).toBe("zh");
+  });
+
+  it("非中文或取不到 → 英文兜底", () => {
+    expect(resolveSystemLocale("en-US")).toBe("en");
+    expect(resolveSystemLocale(undefined)).toBe("en");
+  });
+});