feat(headless): add -y / --yolo CLI flag to sf headless

- HeadlessOptions.yolo added
- parseHeadlessArgs handles --yolo and -y (short form)
- SF_YOLO=1 is injected into the RPC child env when flag is set
- AutoSession._loadPersistedModeState() checks SF_YOLO=1 and
  auto-activates YOLO mode (build+autonomous+deep+unrestricted)
  on session startup

Usage:
  sf headless -y autonomous       # YOLO + autonomous mode
  sf headless --yolo next         # YOLO + run next unit

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/headless.ts

@@ -200,6 +200,7 @@ export interface HeadlessOptions {
 	eventFilter?: Set<string>; // filter JSONL output to specific event types
 	resumeSession?: string; // session ID to resume (--resume <id>)
 	bare?: boolean; // --bare: suppress CLAUDE.md/AGENTS.md, user skills, project preferences
+	yolo?: boolean; // --yolo / -y: activate YOLO mode (build+autonomous+deep+unrestricted)
 }
 
 /**
@@ -381,7 +382,9 @@ export function parseHeadlessArgs(argv: string[]): HeadlessOptions {
 		const arg = args[i];
 		if (arg === "headless") continue;
 
-		if (arg.startsWith("--")) {
+		if (arg === "-y") {
+			options.yolo = true;
+		} else if (arg.startsWith("--")) {
 			if (arg === "--timeout" && i + 1 < args.length) {
 				options.timeout = parseInt(args[++i], 10);
 				if (Number.isNaN(options.timeout) || options.timeout < 0) {
@@ -460,6 +463,8 @@ export function parseHeadlessArgs(argv: string[]): HeadlessOptions {
 				options.resumeSession = args[++i];
 			} else if (arg === "--bare") {
 				options.bare = true;
+			} else if (arg === "--yolo") {
+				options.yolo = true;
 			} else if (commandSeen) {
 				options.commandArgs.push(arg);
 			}
@@ -864,6 +869,7 @@ async function runHeadlessOnce(
 	clientOptions.env = {
 		...((clientOptions.env as Record<string, string>) || {}),
 		SF_HEADLESS: "1",
+		...(options.yolo ? { SF_YOLO: "1" } : {}),
 	};
 	// Propagate --bare to the child process
 	if (options.bare) {

src/resources/extensions/sf/auto/session.js

@@ -118,6 +118,10 @@ export class AutoSession {
 		// Always stamp surface from env: persisted value reflects previous launch's
 		// surface and should not override the current surface detection.
 		this.surface = detectSurface();
+		// Auto-activate YOLO when SF_YOLO=1 (set by --yolo / -y CLI flag)
+		if (process.env.SF_YOLO === "1" && !this.yolo) {
+			this.toggleYolo();
+		}
 	}
 
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