[Multi-User Part 4]: Authenticate using API Tokens (#513)

### ✨ New
- Use API keys to authenticate from Desktop, Obsidian, Emacs clients
- Create API, UI on web app config page to CRUD API Keys
- Create user API keys table and functions to CRUD them in Database

### 🧪 Improve
- Default to better search model, [gte-small](https://huggingface.co/thenlper/gte-small), to improve search quality
- Only load chat model to GPU if enough space, throw error on load failure
- Show encoding progress, truncate headings to max chars supported
- Add instruction to create db in Django DB setup Readme

### ⚙️ Fix
- Fix error handling when configure offline chat via Web UI
- Do not warn in anon mode about Google OAuth env vars not being set
- Fix path to load static files when server started from project root

src/interface/desktop/renderer.js

@@ -181,6 +181,17 @@ urlInput.addEventListener('blur', async () => {
     urlInput.value = url;
 });
 
+const khojKeyInput = document.getElementById('khoj-access-key');
+(async function() {
+    const token = await window.tokenAPI.getToken();
+    khojKeyInput.value = token;
+})();
+
+khojKeyInput.addEventListener('blur', async () => {
+    const token = await window.tokenAPI.setToken(khojKeyInput.value.trim());
+    khojKeyInput.value = token;
+});
+
 const syncButton = document.getElementById('sync-data');
 const syncForceToggle = document.getElementById('sync-force');
 syncButton.addEventListener('click', async () => {