Add Pi Research Agent package

Autonomous research agent with web search, source analysis, and report synthesis.
Built on Pi agent core. Available as CLI, programmatic API, and MCP server.

Features:
- 4 built-in tools: web_search, read_url, save_note, synthesize_report
- CLI with TUI and print modes
- Programmatic API via ResearchAgent class
- MCP server with 3 tools: research, quick_search, read_url
- Skills system for custom research behavior
- Automatic .env file loading for API keys
- Configurable max turns, output formats (markdown/JSON/bullet)
- Automatic report saving to research-output/

packages/research-agent/examples/custom-model.ts

@@ -0,0 +1,40 @@
+/**
+ * Custom Model Example
+ *
+ * Demonstrates how to use a custom model with the ResearchAgent.
+ *
+ * Run with:
+ *   TAVILY_API_KEY=*** \
+ *   OPENROUTER_API_KEY=*** \
+ *   npx tsx examples/custom-model.ts
+ */
+
+import { getModels } from "@earendil-works/pi-ai";
+import { ResearchAgent } from "../src/index.ts";
+
+const models = getModels("openrouter");
+const gpt4o = models.find((m) => m.id === "openai/gpt-4o");
+
+if (!gpt4o) {
+	console.error("GPT-4o model not found");
+	process.exit(1);
+}
+
+const agent = new ResearchAgent({
+	model: gpt4o,
+	thinkingLevel: "high",
+	maxTurns: 15,
+});
+
+agent.subscribe((event) => {
+	if (event.type === "message_update" && event.assistantMessageEvent.type === "text_delta") {
+		process.stdout.write(event.assistantMessageEvent.delta);
+	}
+});
+
+const topic = "Comparison of renewable energy storage solutions";
+console.log(`Researching: ${topic}\n`);
+
+const result = await agent.research(topic);
+
+console.log("\n\n" + result.report);