docs: update Kobo setup to use API key authentication

- Replace username/password authentication with API key in sync URL
- Update configuration examples to show API key in URL path
- Add instructions for copying API key from Device Management
- Update OPDS catalog URL to include token parameter
- Fix troubleshooting section for API key authentication
- Document where to find API key and sync URL in UI
- Update SSL/TLS examples with API key approach

docs/user/devices/kobo-setup.md

@@ -99,6 +99,8 @@ Your device is now registered and ready for configuration!
 
 ### Step 3: Add Bookhoard Sync Configuration
 
+After device registration is complete, you'll receive an API key and sync URL from Bookhoard.
+
 Add the following section to the end of your `Kobo eReader.conf` file:
 
 ```ini
@@ -107,16 +109,30 @@ Add the following section to the end of your `Kobo eReader.conf` file:
 KoboStoreSyncDisabled=true
 
 [Sync]
-# Bookhoard Sync Configuration
-ServerURL=http://YOUR_COMPUTER_IP:8765/api/sync/kobo
+# Bookhoard Sync Configuration (from Device Management page)
+ServerURL=http://YOUR_COMPUTER_IP:8765/api/sync/kobo/YOUR_API_KEY
 AutoSyncEnabled=true
 SyncFrequency=5
-
-# Authentication
-Username=YOUR_BOOKHOARD_USERNAME
-Password=YOUR_BOOKHOARD_PASSWORD
 ```
 
+**Where to find these values**:
+- `YOUR_COMPUTER_IP`: Your Bookhoard server's IP address (e.g., 192.168.1.100)
+- `YOUR_API_KEY`: Copy from Bookhoard Device Management → Your Kobo Device → "Copy Sync URL"
+
+**Example configuration**:
+```ini
+[Sync]
+ServerURL=http://192.168.1.100:8765/api/sync/kobo/dev_abc123def456
+AutoSyncEnabled=true
+SyncFrequency=5
+```
+
+**Important Notes**:
+- The API key is generated during device registration
+- You can regenerate the API key anytime from Device Management if needed
+- Keep your API key confidential like a password
+- Bookhoard uses revocable API keys for security (not username/password)
+
 **Replace the following with your actual values**:
 - `YOUR_COMPUTER_IP`: Your computer's local IP address (e.g., 192.168.1.100)
 - `YOUR_BOOKHOARD_USERNAME`: Your Bookhoard email or username
@@ -204,15 +220,16 @@ OPDS (Open Publication Distribution System) allows your Kobo to **wirelessly dow
 [FeatureSettings]
 # Enable OPDS catalog
 OPDSCatalogEnabled=true
-OPDSCatalogURL=http://YOUR_COMPUTER_IP:8765/opds/devices/YOUR_DEVICE_ID/catalog
+OPDSCatalogURL=http://YOUR_COMPUTER_IP:8765/opds/devices/YOUR_DEVICE_ID/catalog?token=YOUR_API_KEY
 
 # Example:
-# OPDSCatalogURL=http://192.168.1.100:8765/opds/devices/kobo-clara-123/catalog
+# OPDSCatalogURL=http://192.168.1.100:8765/opds/devices/kobo-clara-123/catalog?token=dev_abc123def456
 ```
 
 4. Replace:
    - `YOUR_COMPUTER_IP`: Your Bookhoard server IP
    - `YOUR_DEVICE_ID`: Your Kobo's device ID from Bookhoard Device Management
+   - `YOUR_API_KEY`: Your Kobo device's API key (same as in sync URL)
 
 5. Save the file and safely eject your Kobo
 
@@ -424,9 +441,11 @@ If you have SSL/TLS configured on Bookhoard:
 
 ```ini
 [Sync]
-ServerURL=https://bookhoard.yourdomain.com/api/sync/kobo
+ServerURL=https://bookhoard.yourdomain.com/api/sync/kobo/YOUR_API_KEY
 ```
 
+Replace `YOUR_API_KEY` with your device's API key from Bookhoard Device Management.
+
 Kobo will automatically trust the certificate if properly configured.
 
 ## Troubleshooting
@@ -455,14 +474,14 @@ Kobo will automatically trust the certificate if properly configured.
 
 ### Authentication Failed
 
-**Problem**: "Authentication failed" or "Invalid credentials"
-
+**Problem**: "Authentication failed" or "Invalid API key"
+ 
 **Solutions**:
-1. Verify username and password in config file
-2. Check your account is active and not locked
-3. Try logging in to Bookhoard web interface
-4. Ensure password doesn't contain special characters that need escaping
-5. Reset password if needed
+1. Verify the API key in your sync URL matches the one in Bookhoard Device Management
+2. Check that device is approved in Bookhoard (not pending)
+3. Try regenerating the API key from Device Management page
+4. Ensure the sync URL is complete (includes the API key)
+5. Copy the sync URL directly from Device Management → "Copy Sync URL" button
 
 ### Configuration File Not Saving
 
@@ -532,10 +551,10 @@ For access outside your home network:
 1. Set up port forwarding on your router (port 8765)
 2. Configure SSL/TLS on Bookhoard
 3. Use a dynamic DNS service for constant hostname
-4. Update Kobo config with public URL:
+4. Update Kobo config with public URL including API key:
    ```ini
    [Sync]
-   ServerURL=https://yourdomain.com/api/sync/kobo
+   ServerURL=https://yourdomain.com/api/sync/kobo/YOUR_API_KEY
    ```
 
 ## Performance Optimization