[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/preload.js

@@ -47,3 +47,8 @@ contextBridge.exposeInMainWorld('hostURLAPI', {
 contextBridge.exposeInMainWorld('syncDataAPI', {
     syncData: (regenerate) => ipcRenderer.invoke('syncData', regenerate)
 })
+
+contextBridge.exposeInMainWorld('tokenAPI', {
+    setToken: (token) => ipcRenderer.invoke('setToken', token),
+    getToken: () => ipcRenderer.invoke('getToken')
+})