Harden web root, secrets and realtime auth

- .htaccess: refuse .git, .env, docker, nodejs, sdlc*, scripts, archives and
  app internals; security headers, HSTS over TLS, optional HTTPS redirect
- uploads served through app/file.php to signed-in users only
- Apache/PHP hardening config for the container (ServerTokens, expose_php)
- least-privilege DB account and APP_SECRET_KEY via docker/php/provision.php;
  SMTP passwords re-encrypted with a random IV (secret_box.php)
- Socket.IO rooms from a PHP-signed token; /emit and cron refuse empty secrets
- escape notification text; CLI guards on build scripts; no fixed demo password

nodejs/server.js

@@ -1,9 +1,42 @@
 require('dotenv').config();
 
+const crypto     = require('crypto');
 const express    = require('express');
 const { createServer } = require('http');
 const { Server } = require('socket.io');
 
+const EMIT_SECRET = process.env.EMIT_SECRET || '';
+if (!EMIT_SECRET) {
+    // Without a secret anyone could call /emit and sign socket tokens.
+    console.error('EMIT_SECRET is not set — refusing to start.');
+    process.exit(1);
+}
+
+// Socket tokens are signed with a key derived from EMIT_SECRET, so a token can
+// never double as the /emit secret. Must match socket_token() in include_ending.php.
+const SOCKET_KEY = crypto.createHmac('sha256', EMIT_SECRET).update('socket-token').digest();
+
+function safeEqual(a, b) {
+    const x = Buffer.from(String(a));
+    const y = Buffer.from(String(b));
+    return x.length === y.length && crypto.timingSafeEqual(x, y);
+}
+
+// Token = base64url(JSON {c, u, r, exp}) + "." + base64url(HMAC-SHA256(payload)).
+// Returns the claims, or null when the token is missing, forged or expired.
+function verifySocketToken(token) {
+    if (typeof token !== 'string' || token.indexOf('.') < 1) return null;
+    const [payload, sig] = token.split('.', 2);
+    const expected = crypto.createHmac('sha256', SOCKET_KEY).update(payload).digest('base64url');
+    if (!safeEqual(sig, expected)) return null;
+    let claims;
+    try { claims = JSON.parse(Buffer.from(payload, 'base64url').toString('utf8')); }
+    catch (e) { return null; }
+    if (!claims || !Number.isInteger(claims.c) || claims.c <= 0) return null;
+    if (!Number.isInteger(claims.exp) || claims.exp < Math.floor(Date.now() / 1000)) return null;
+    return claims;
+}
+
 const app        = express();
 const httpServer = createServer(app);
 const io         = new Server(httpServer, {
@@ -17,8 +50,8 @@ app.use(express.json());
 // Body: { event, data, company_id }
 //
 app.post('/emit', (req, res) => {
-    const secret = req.headers['x-emit-secret'];
-    if (secret !== process.env.EMIT_SECRET) {
+    const secret = req.headers['x-emit-secret'] || '';
+    if (!safeEqual(secret, EMIT_SECRET)) {
         return res.status(403).json({ ok: false, message: 'Forbidden' });
     }
 
@@ -46,28 +79,26 @@ app.post('/emit', (req, res) => {
 });
 
 // ── /health ───────────────────────────────────────────────────────────────────
+// Deliberately public (used by uptime checks); reports status only.
 app.get('/health', (req, res) => {
-    res.json({
-        status: 'ok',
-        uptime: Math.floor(process.uptime()),
-        connections: io.engine.clientsCount,
-        memory_mb: Math.round(process.memoryUsage().rss / 1024 / 1024 * 10) / 10
-    });
+    res.json({ status: 'ok' });
 });
 
 // ── WebSocket connections ─────────────────────────────────────────────────────
-// Each browser tab connects here on page load.
-// It joins a room named company_<id> so events stay isolated per company.
+// Each browser tab connects here on page load with a token PHP signed for the
+// signed-in user (include_ending.php). Rooms come only from the verified token —
+// never from values the browser chooses — so a visitor cannot listen to another
+// company's events.
 //
-io.on('connection', (socket) => {
-    const company_id = socket.handshake.query.company_id;
-    const user_id    = socket.handshake.query.user_id;
-    const role       = socket.handshake.query.role || 'viewer';
+io.use((socket, next) => {
+    const claims = verifySocketToken(socket.handshake.auth && socket.handshake.auth.token);
+    if (!claims) return next(new Error('unauthorized'));
+    socket.data.claims = claims;
+    next();
+});
 
-    if (!company_id) {
-        socket.disconnect();
-        return;
-    }
+io.on('connection', (socket) => {
+    const { c: company_id, u: user_id, r: role } = socket.data.claims;
 
     socket.join(`company_${company_id}`);