Migrate Journals and Badges modules to Aether API V3 CRUD endpoints and fix Svelte 5 / Dexie integration issues.

documentation/V3_FRONTEND_API_GUIDE.md

@@ -73,9 +73,56 @@ Use the `q` property in your search body for a general keyword search across ind
 }
 ```
 
+### D. Supported Search Operators
+The `op` property in a `SearchFilter` supports the following values:
+
+| Operator | SQL equivalent | Description |
+| --- | --- | --- |
+| `eq` | `=` | Equal to |
+| `ne` | `!=` | Not equal to |
+| `gt` | `>` | Greater than |
+| `gte` | `>=` | Greater than or equal to |
+| `lt` | `<` | Less than |
+| `lte` | `<=` | Less than or equal to |
+| `in` | `IN (...)` | Matches any value in a provided list |
+| `is_null` | `IS NULL` | Field is null (ignores `value`) |
+| `is_not_null` | `IS NOT NULL` | Field is not null (ignores `value`) |
+| `like` | `LIKE` | Standard SQL LIKE (requires manual `%` in `value`) |
+| `contains` | `LIKE %val%` | Wraps value in `%` automatically |
+| `startswith` | `LIKE val%` | Appends `%` to value automatically |
+| `endswith` | `LIKE %val` | Prepends `%` to value automatically |
+
 ---
 
-## 3. Best Practices for V3
+## 4. Authentication in V3
+
+V3 supports multiple authentication methods. The backend resolves these automatically.
+
+### A. Standard Requests (Header)
+For most API calls, use the standard Bearer token in the `Authorization` header.
+
+```ts
+// Example: Setting the JWT in headers
+headers: {
+    "Authorization": `Bearer ${user_jwt_token}`
+}
+```
+
+### B. Secure File Downloads (URL Parameter)
+**Crucial for `hosted_file` and `event_file`**: To allow browsers to download files without complex header modifications, you can pass the JWT directly in the URL.
+
+```ts
+// Example: Creating a secure download link
+// GET /v3/crud/hosted_file/{id}/?jwt={token}
+const downloadUrl = `${BASE_URL}/hosted_file/${fileId}/?jwt=${jwtToken}`;
+```
+
+### C. Legacy Fallback (X-Account-ID)
+For development and backward compatibility, the `X-Account-ID` header is still supported but should be phased out in favor of JWT.
+
+---
+
+## 5. Best Practices for V3
 
 1.  **Use `view` for Rich Data**: Instead of manually joining data in separate calls, use `?view=enriched` or `?view=detail` if defined in the backend.
 2.  **Hybrid Search**: Use query parameters for simple toggles (enabled/hidden) and the POST body for complex logic.