Limit request sizes, answer 413, stop cleanly on SIGTERM

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UaC9HmtHMdRP8dAbN4wAKj

tasks.js

@@ -12,7 +12,7 @@ const users = require('./users');
 const file = () => path.join(users.dir(), 'tasks.json'); // each person has their own
 const load = () => { try { return JSON.parse(fs.readFileSync(file(), 'utf8')); } catch { return { lists: [{ id: 'inbox', name: 'Tasks' }], tasks: [] }; } };
 const save = d => atomicWrite(file(), JSON.stringify(d, null, 2), { mode: 0o600 });
-const readBody = req => new Promise((ok, no) => { const c = []; req.on('data', d => c.push(d)); req.on('end', () => ok(Buffer.concat(c).toString())); req.on('error', no); });
+const { readBody } = require('./body');
 const json = (res, code, obj) => { res.writeHead(code, { 'content-type': 'application/json' }); res.end(JSON.stringify(obj)); };
 const isLocal = id => String(id || '').startsWith('local:');
 const COLORS = ['#4f7cff', '#2f9e6e', '#e0742b', '#d9453a', '#8a5cf0', '#e5a00d'];