Add toggle for AI character selection parameter

- Add setting to control whether AI can choose character
- Modify function schema based on user settings
- Only expose character parameter to AI when setting is enabled
- Update test function to reflect current settings
- Provide separate documentation for each setting mode
- Default is character selection disabled, set by extension user

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

example.html

@@ -15,6 +15,11 @@
                 <label for="sillybubble_render_in_collapse">Render bubbles in collapsed tool calls</label>
             </div>
 
+            <div class="sillybubble_block flex-container">
+                <input id="sillybubble_use_character_param" type="checkbox" />
+                <label for="sillybubble_use_character_param">Let AI choose character (expose character parameter to AI)</label>
+            </div>
+
             <div class="sillybubble_block flex-container">
                 <label for="sillybubble_image_url">Image Service URL (full URL including https://):</label>
                 <input id="sillybubble_image_url" type="text" class="text_pole" placeholder="https://calista.the.sexiest.cat/image.php" />
@@ -68,21 +73,33 @@
                         <li>"Include functions in context" is checked</li>
                         <li>The function appears in the function list</li>
                     </ol>
-                    <p><strong>🚨 REQUIRED SETUP:</strong> You MUST add the following to your system prompt or character card:</p>
-                    <pre>You have access to a function called generateChatBubbleImage(text, character, bubble_type, style) that creates character-styled chat bubbles.
+                    <p><strong>🚨 REQUIRED SETUP:</strong> You MUST add one of the following to your system prompt or character card (depending on your settings):</p>
+                    
+                    <p><strong>If "Let AI choose character" is disabled (default):</strong></p>
+                    <pre>You have access to a function called generateChatBubbleImage(text, bubble_type) that creates styled chat bubbles.
+
+The function parameters are:
+- text: The text to display in the chat bubble (required string)
+- bubble_type: The type of bubble to use (optional string: "speech" or "thought")
+
+When you want to create a chat bubble, call this function with the text you want to display.
+Example usage:
+generateChatBubbleImage("Hello world!")
+generateChatBubbleImage("I'm thinking...", "thought")</pre>
+
+                    <p><strong>If "Let AI choose character" is enabled:</strong></p>
+                    <pre>You have access to a function called generateChatBubbleImage(text, character, bubble_type) that creates character-styled chat bubbles.
 
 The function parameters are:
 - text: The text to display in the chat bubble (required string)
 - character: The character to use for the bubble (optional string: "Example", "Bianca", etc.)
 - bubble_type: The type of bubble to use (optional string: "speech" or "thought")
-- style: Legacy parameter for visual style (optional string: "default", "modern", "retro", or "minimal")
 
 When you want to create a chat bubble, call this function with the text you want to display.
 Example usage:
 generateChatBubbleImage("Hello world!")
 generateChatBubbleImage("Hello from Bianca", "Bianca")
-generateChatBubbleImage("I'm thinking...", "Example", "thought")
-generateChatBubbleImage("Hello in retro style", null, null, "retro")</pre>
+generateChatBubbleImage("I'm thinking...", "Example", "thought")</pre>
                     <p><strong>ALTERNATIVE:</strong> If the AI can't call the function directly, you can instruct it to respond with Markdown formatted like this:</p>
                     <pre>![](image.php?q=Hello%20world)</pre>
                 </div>