feat: auto memory pipeline — host-driven Memento recall/reflect

Add automatic memory integration so EJClaw host directly calls Memento
MCP for recall at session start and reflect on compact, removing
reliance on agent voluntary tool use.

Stage 1: New sessions get room memory briefing injected into system
prompt (CLAUDE.md / AGENTS.md) via host-side MCP client.

Stage 2: PreCompact hook automatically calls reflect + remember to
persist session summaries as room-memory fragments.

Also restores missing source files (token-rotation, codex-token-rotation,
claude-usage exports) to fix full build from source.

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

src/token-rotation.ts

@@ -0,0 +1,62 @@
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+
+const HOST_CLAUDE_DIR = path.join(os.homedir(), '.claude');
+const CLAUDE_ACCOUNTS_DIR = path.join(os.homedir(), '.claude-accounts');
+
+let activeIndex = 0;
+const rateLimitedAccounts = new Set<number>();
+
+function listClaudeAccounts(): string[] {
+  if (!fs.existsSync(CLAUDE_ACCOUNTS_DIR)) return [];
+
+  return fs
+    .readdirSync(CLAUDE_ACCOUNTS_DIR, { withFileTypes: true })
+    .filter((entry) => entry.isDirectory() && /^\d+$/.test(entry.name))
+    .sort((a, b) => Number(a.name) - Number(b.name))
+    .map((entry) => path.join(CLAUDE_ACCOUNTS_DIR, entry.name));
+}
+
+function copyIfExists(src: string, dst: string): void {
+  if (!fs.existsSync(src)) return;
+  fs.mkdirSync(path.dirname(dst), { recursive: true });
+  fs.copyFileSync(src, dst);
+}
+
+function syncHostClaudeAccount(accountDir: string): void {
+  copyIfExists(
+    path.join(accountDir, '.credentials.json'),
+    path.join(HOST_CLAUDE_DIR, '.credentials.json'),
+  );
+  copyIfExists(path.join(accountDir, 'settings.json'), path.join(HOST_CLAUDE_DIR, 'settings.json'));
+}
+
+export function getTokenCount(): number {
+  const accounts = listClaudeAccounts();
+  return accounts.length > 0 ? accounts.length : 1;
+}
+
+export function rotateToken(_reason?: string): boolean {
+  const accounts = listClaudeAccounts();
+  if (accounts.length <= 1) return false;
+
+  rateLimitedAccounts.add(activeIndex);
+
+  const candidates = accounts.map((_, index) => index);
+  const nextIndex =
+    candidates.find(
+      (index) => index !== activeIndex && !rateLimitedAccounts.has(index),
+    ) ??
+    candidates.find((index) => index !== activeIndex);
+
+  if (nextIndex === undefined) return false;
+
+  syncHostClaudeAccount(accounts[nextIndex]);
+  activeIndex = nextIndex;
+  return true;
+}
+
+export function markTokenHealthy(): void {
+  rateLimitedAccounts.delete(activeIndex);
+}