Implement runtime-configurable features

In particular these things can now be enabled or disabled depending on
the user's requirements:

- A netbanner (previously implemented, later removed, hard-coded into fork)
- Interactions with a scheduler server (previously implemented in branch cgi-storage)

5 files changed, 110 insertions, 6 deletions

diff --git a/srs-anywhere-config.js b/srs-anywhere-config.js
new file mode 100644
index 0000000..77c5332
--- /dev/null
+++ b/srs-anywhere-config.js
@@ -0,0 +1,21 @@
+/* Copyright © 2025 - 2026 Jakob L. Kreuze
+
+   This file is part of SRS Anywhere.
+
+   SRS Anywhere is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   SRS Anywhere is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+   Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public
+   License along with SRS Anywhere. If not, see <https://www.gnu.org/licenses/>. */
+
+const SRS_ANYWHERE_CONFIG = {
+  banner: false,
+  network: false
+};
diff --git a/srs-anywhere-network.js b/srs-anywhere-network.js
index 8fe925b..8d972cc 100644
--- a/srs-anywhere-network.js
+++ b/srs-anywhere-network.js
@@ -1,4 +1,4 @@
-/* Copyright © 2025 Jakob L. Kreuze
+/* Copyright © 2025 - 2026 Jakob L. Kreuze
 
    This file is part of SRS Anywhere.
 
@@ -15,7 +15,21 @@
    You should have received a copy of the GNU Affero General Public
    License along with SRS Anywhere. If not, see <https://www.gnu.org/licenses/>. */
 
-window.addEventListener("load", () => {
+function enableInputs() {
+  const target = document.querySelector('#cards-input');
+  const el1 = document.createElement('input');
+  el1.type = "text";
+  el1.id = "network-password";
+  const el2 = document.createElement('button');
+  el2.id = "open-network";
+  el2.innerText = "Go!";
+  const el3 = document.createElement('br');
+  target.before(el1, el2, el3);
+}
+
+function enableNetworkFeatures() {
+  enableInputs();
+
   const passwordField = document.getElementById('network-password');
 
   const urlParams = new URLSearchParams(window.location.search);
@@ -47,6 +61,12 @@ window.addEventListener("load", () => {
     };
     xhr.send();
   });
+}
+
+window.addEventListener("load", () => {
+  if (SRS_ANYWHERE_CONFIG.network) {
+    enableNetworkFeatures();
+  }
 });
 
 const downloadJSONOld = downloadJSON;
diff --git a/srs-anywhere.css b/srs-anywhere.css
index bcef4fb..78e6e2d 100644
--- a/srs-anywhere.css
+++ b/srs-anywhere.css
@@ -155,3 +155,36 @@ textarea {
 #flashcard img {
     width: 100%;
 }
+
+* {
+    box-sizing: border-box;
+    margin: 0;
+    padding: 0;
+}
+
+.banner {
+    position: fixed;
+    width: 100%;
+    color: white;
+    text-align: center;
+    font-weight: bold;
+    line-height: 16px;
+    font-size: 12px;
+    z-index: 100;
+}
+
+.top-banner {
+    top: 0;
+    background-color: #008000;
+}
+
+.bottom-banner {
+    bottom: 0;
+    background-color: #008000;
+}
+
+.content {
+    padding: 20px;
+    max-width: 800px;
+    margin: auto;
+}
diff --git a/srs-anywhere.html b/srs-anywhere.html
index 3897063..83b7633 100644
--- a/srs-anywhere.html
+++ b/srs-anywhere.html
@@ -8,9 +8,15 @@
     <link rel="icon" href="srs-anywhere.ico">
   </head>
   <body style="display: flex;">
-    <div id="flashcard">
-      <div id="flashcard-front"></div>
-      <div id="flashcard-back"></div>
+    <div class="banner top-banner" hidden>UNCLASSIFIED</div>
+
+    <div class="banner bottom-banner" hidden>UNCLASSIFIED</div>
+
+    <div class="content">
+      <div id="flashcard">
+        <div id="flashcard-front"></div>
+        <div id="flashcard-back"></div>
+      </div>
     </div>
 
     <div class="status-section">
@@ -76,6 +82,7 @@
 
     <script src="srs-anywhere.js"></script>
     <script src="srs-anywhere-network.js"></script>
+    <script src="srs-anywhere-config.js"></script>
     <script src="srs-anywhere-custom-card-types.js"></script>
   </body>
 </html>
diff --git a/srs-anywhere.js b/srs-anywhere.js
index 8f77f02..1348a37 100644
--- a/srs-anywhere.js
+++ b/srs-anywhere.js
@@ -1,4 +1,4 @@
-/* Copyright © 2025 Jakob L. Kreuze
+/* Copyright © 2025 - 2026 Jakob L. Kreuze
 
    This file is part of SRS Anywhere.
 
@@ -482,3 +482,26 @@ window.addEventListener('keydown', (event) => {
     endReview();
   }
 });
+
+/***********************************************************************
+ * Runtime configuration                                               *
+ ***********************************************************************/
+
+function enableClassificationBanner() {
+  console.log('here');
+  const banners = document.querySelectorAll('div.banner');
+  banners.forEach(banner => {
+    banner.removeAttribute('hidden');
+  });
+
+  const buttonContainer = document.getElementById('button-container');
+  if (buttonContainer) {
+    buttonContainer.style.bottom = '1rem';
+  }
+}
+
+window.addEventListener('load', () => {
+  if (SRS_ANYWHERE_CONFIG.banner) {
+    enableClassificationBanner();
+  }
+});