add security hardening features (#543)

* add security hardening features

- Add authentication vault (`auth save/login/list/show/delete`) so credentials are stored locally and never exposed to the LLM (fixes Snyk W007)
- Add `--content-boundaries` flag to wrap page-sourced output in structural markers, helping LLMs distinguish tool output from untrusted page content (fixes Snyk W011)
- Add `--allowed-domains` flag to restrict browser navigation to trusted domains
- Add `--action-policy` for static allow/deny gating of action categories, with opt-in `--confirm-actions`/`--confirm-interactive` for orchestrator or human-in-the-loop confirmation
- Add `--max-output` flag to truncate large page outputs, preventing context flooding
- New docs page at /security, updated README, SKILL.md, CLI help text, and templates

* fixes

* fixes

* fixes

* fixes

* fixes

* fixes

* fixes

* docs

src/confirmation.ts

@@ -0,0 +1,53 @@
+import { randomBytes } from 'node:crypto';
+
+interface PendingConfirmation {
+  id: string;
+  action: string;
+  category: string;
+  description: string;
+  command: Record<string, unknown>;
+  timer: ReturnType<typeof setTimeout>;
+}
+
+const AUTO_DENY_TIMEOUT_MS = 60_000;
+
+const pending = new Map<string, PendingConfirmation>();
+
+function generateId(): string {
+  return `c_${randomBytes(8).toString('hex')}`;
+}
+
+export function requestConfirmation(
+  action: string,
+  category: string,
+  description: string,
+  command: Record<string, unknown>
+): { confirmationId: string } {
+  const id = generateId();
+
+  const timer = setTimeout(() => {
+    pending.delete(id);
+  }, AUTO_DENY_TIMEOUT_MS);
+
+  pending.set(id, {
+    id,
+    action,
+    category,
+    description,
+    command,
+    timer,
+  });
+
+  return { confirmationId: id };
+}
+
+export function getAndRemovePending(
+  id: string
+): { command: Record<string, unknown>; action: string } | null {
+  const entry = pending.get(id);
+  if (!entry) return null;
+
+  clearTimeout(entry.timer);
+  pending.delete(id);
+  return { command: entry.command, action: entry.action };
+}