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/attachments.test.ts

@@ -0,0 +1,42 @@
+/**
+ * splitImageAttachments unit tests: splitting "[attached image: …]" attachment
+ * lines out of user text — scratchpad paths map to the session file endpoint,
+ * http(s) URLs are quoted as-is, and unrecognized lines stay in the text.
+ */
+import { describe, expect, it } from "vitest";
+import { splitImageAttachments } from "../src/lib/attachments";
+
+describe("splitImageAttachments", () => {
+  it("scratchpad 路径行 → 会话文件端点，正文保留", () => {
+    const { text, images } = splitImageAttachments(
+      "看看这张图\n\n[attached image: /home/u/.penguin/data/p1/agents/a1/scratchpad/session-20260712-abc/upload-1752300000000-0.png]",
+    );
+    expect(text).toBe("看看这张图");
+    expect(images).toEqual([
+      "/api/sessions/session-20260712-abc/scratchpad/upload-1752300000000-0.png",
+    ]);
+  });
+
+  it("http(s) URL 直引；多附件按顺序", () => {
+    const { text, images } = splitImageAttachments(
+      "[attached image: https://example.com/a.png]\n[attached image: /x/scratchpad/s1/b.png]",
+    );
+    expect(text).toBe("");
+    expect(images).toEqual(["https://example.com/a.png", "/api/sessions/s1/scratchpad/b.png"]);
+  });
+
+  it("识别不出的行保留在文本（说明行 / 非本系统路径）", () => {
+    const { text, images } = splitImageAttachments(
+      "hi\n\n[an attached image could not be saved and was dropped]\n[attached image: /etc/passwd]",
+    );
+    expect(images).toEqual([]);
+    expect(text).toContain("could not be saved");
+    expect(text).toContain("[attached image: /etc/passwd]");
+  });
+
+  it("无附件行原样返回", () => {
+    const { text, images } = splitImageAttachments("普通消息");
+    expect(text).toBe("普通消息");
+    expect(images).toEqual([]);
+  });
+});