Add env-driven SMTP and app identity settings for PocketBase

- pb_hooks/main.pb.js: bootstrap hook applying SMTP + meta settings from
  env vars on every boot (mail disabled when SMTP_HOST is unset)
- docker-compose.yml: expose SMTP_* / PB_APP_URL on the pocketbase service
- pocketbase/Dockerfile: bundle pb_hooks
- README: document the new variables

pocketbase/Dockerfile

@@ -12,6 +12,7 @@ RUN curl -fsSL "https://github.com/pocketbase/pocketbase/releases/download/v${PB
     && rm pb.zip
 
 COPY pb_migrations ./pb_migrations
+COPY pb_hooks ./pb_hooks
 COPY entrypoint.sh ./
 RUN chmod +x entrypoint.sh pocketbase
 

pocketbase/pb_hooks/main.pb.js

@@ -0,0 +1,36 @@
+/**
+ * Apply app identity and SMTP settings from environment variables on every
+ * boot, so mail config stays declarative (docker-compose / Coolify env vars).
+ * These values win over the admin UI (Settings → Mail) — change them via env.
+ */
+onBootstrap((e) => {
+    e.next();
+
+    const settings = $app.settings();
+
+    // App identity, used in transactional emails (verification, reset, etc.)
+    settings.meta.appName = "PokeShare";
+    const appUrl = $os.getenv("PB_APP_URL");
+    if (appUrl) settings.meta.appUrl = appUrl;
+
+    const host = $os.getenv("SMTP_HOST");
+    if (!host) {
+        // No SMTP configured — save identity settings and keep mail disabled
+        $app.save(settings);
+        return;
+    }
+
+    const senderAddress = $os.getenv("SMTP_SENDER_ADDRESS");
+    const senderName = $os.getenv("SMTP_SENDER_NAME");
+    if (senderAddress) settings.meta.senderAddress = senderAddress;
+    if (senderName) settings.meta.senderName = senderName;
+
+    settings.smtp.enabled = true;
+    settings.smtp.host = host;
+    settings.smtp.port = parseInt($os.getenv("SMTP_PORT") || "587", 10);
+    settings.smtp.username = $os.getenv("SMTP_USERNAME") || "";
+    settings.smtp.password = $os.getenv("SMTP_PASSWORD") || "";
+    settings.smtp.tls = ($os.getenv("SMTP_TLS") || "true") === "true";
+
+    $app.save(settings);
+});