WIP: Major cleanup - move Attachment to consumers, simplify agent API

- Removed Attachment from agent package (now in web-ui/coding-agent)
- Agent.prompt now takes (text, images?: ImageContent[])
- Removed transports from web-ui (duplicate of agent package)
- Updated coding-agent to use local message types
- Updated mom package for new agent API

Remaining: Fix AgentInterface.ts to compose UserMessageWithAttachments

packages/coding-agent/src/core/tools/bash.ts

@@ -2,7 +2,7 @@ import { randomBytes } from "node:crypto";
 import { createWriteStream } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import type { AgentTool } from "@mariozechner/pi-ai";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { Type } from "@sinclair/typebox";
 import { spawn } from "child_process";
 import { getShellConfig, killProcessTree } from "../../utils/shell.js";