move pi-mono into companion-cloud as apps/companion-os

- Copy all pi-mono source into apps/companion-os/
- Update Dockerfile to COPY pre-built binary instead of downloading from GitHub Releases
- Update deploy-staging.yml to build pi from source (bun compile) before Docker build
- Add apps/companion-os/** to path triggers
- No more cross-repo dispatch needed

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/coding-agent/test/session-manager/save-entry.test.ts

@@ -0,0 +1,62 @@
+import { describe, expect, it } from "vitest";
+import {
+  type CustomEntry,
+  SessionManager,
+} from "../../src/core/session-manager.js";
+
+describe("SessionManager.saveCustomEntry", () => {
+  it("saves custom entries and includes them in tree traversal", () => {
+    const session = SessionManager.inMemory();
+
+    // Save a message
+    const msgId = session.appendMessage({
+      role: "user",
+      content: "hello",
+      timestamp: 1,
+    });
+
+    // Save a custom entry
+    const customId = session.appendCustomEntry("my_data", { foo: "bar" });
+
+    // Save another message
+    const msg2Id = session.appendMessage({
+      role: "assistant",
+      content: [{ type: "text", text: "hi" }],
+      api: "anthropic-messages",
+      provider: "anthropic",
+      model: "test",
+      usage: {
+        input: 1,
+        output: 1,
+        cacheRead: 0,
+        cacheWrite: 0,
+        totalTokens: 2,
+        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+      },
+      stopReason: "stop",
+      timestamp: 2,
+    });
+
+    // Custom entry should be in entries
+    const entries = session.getEntries();
+    expect(entries).toHaveLength(3);
+
+    const customEntry = entries.find((e) => e.type === "custom") as CustomEntry;
+    expect(customEntry).toBeDefined();
+    expect(customEntry.customType).toBe("my_data");
+    expect(customEntry.data).toEqual({ foo: "bar" });
+    expect(customEntry.id).toBe(customId);
+    expect(customEntry.parentId).toBe(msgId);
+
+    // Tree structure should be correct
+    const path = session.getBranch();
+    expect(path).toHaveLength(3);
+    expect(path[0].id).toBe(msgId);
+    expect(path[1].id).toBe(customId);
+    expect(path[2].id).toBe(msg2Id);
+
+    // buildSessionContext should work (custom entries skipped in messages)
+    const ctx = session.buildSessionContext();
+    expect(ctx.messages).toHaveLength(2); // only message entries
+  });
+});