Merge spike/claude-code-integration: PTY-based Claude Code with multi-agent support

Spike proved: spawning claude -p in a PTY from Rust gets Max subscription
billing. Multi-agent concurrency confirmed with session resumption.
Includes AgentPool REST API, claude-code provider, and spike documentation.

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

# Conflicts:
#	.ignore

frontend/src/components/Chat.tsx

@@ -444,7 +444,8 @@ export function Chat({ projectPath, onCloseProject }: ChatProps) {
 		const messageToSend = messageOverride ?? input;
 		if (!messageToSend.trim() || loading) return;
 
-		if (model.startsWith("claude-")) {
+		const isClaudeCode = model === "claude-code-pty";
+		if (!isClaudeCode && model.startsWith("claude-")) {
 			const hasKey = await api.getAnthropicApiKeyExists();
 			if (!hasKey) {
 				pendingMessageRef.current = messageToSend;
@@ -464,8 +465,13 @@ export function Chat({ projectPath, onCloseProject }: ChatProps) {
 		setStreamingContent("");
 
 		try {
+			const provider = isClaudeCode
+				? "claude-code"
+				: model.startsWith("claude-")
+					? "anthropic"
+					: "ollama";
 			const config: ProviderConfig = {
-				provider: model.startsWith("claude-") ? "anthropic" : "ollama",
+				provider,
 				model,
 				base_url: "http://localhost:11434",
 				enable_tools: enableTools,

frontend/src/components/ChatHeader.tsx

@@ -175,6 +175,11 @@ export function ChatHeader({
 							backgroundSize: "10px",
 						}}
 					>
+						<optgroup label="Claude Code (PTY)">
+							<option value="claude-code-pty">
+								claude-code-pty
+							</option>
+						</optgroup>
 						{(claudeModels.length > 0 || !hasAnthropicKey) && (
 							<optgroup label="Anthropic">
 								{claudeModels.length > 0 ? (

frontend/vite.config.ts

@@ -5,6 +5,7 @@ import { defineConfig } from "vite";
 export default defineConfig(() => ({
   plugins: [react()],
   server: {
+    port: 5173,
     proxy: {
       "/api": {
         target: "http://127.0.0.1:3001",