feat: Add UI for custom tools (#12585)

### Tools list

<img width="2316" height="666" alt="CleanShot 2025-10-03 at 20 42 41@2x"
src="https://github.com/user-attachments/assets/ccbffd16-804d-4eb8-9c64-2d1cfd407e4e"
/>

### Tools form 

<img width="2294" height="2202" alt="CleanShot 2025-10-03 at 20 43
05@2x"
src="https://github.com/user-attachments/assets/9f49aa09-75a1-4585-a09d-837ca64139b8"
/>

## Response

<img width="800" height="2144" alt="CleanShot 2025-10-03 at 20 45 56@2x"
src="https://github.com/user-attachments/assets/b0c3c899-6050-4c51-baed-c8fbec5aae61"
/>

---------

Co-authored-by: Pranav <pranavrajs@gmail.com>
Co-authored-by: Pranav <pranav@chatwoot.com>

enterprise/app/models/concerns/toolable.rb

@@ -3,7 +3,10 @@ module Concerns::Toolable
 
   def tool(assistant)
     custom_tool_record = self
+    # Convert slug to valid Ruby constant name (replace hyphens with underscores, then camelize)
+    class_name = custom_tool_record.slug.underscore.camelize
 
+    # Always create a fresh class to reflect current metadata
     tool_class = Class.new(Captain::Tools::HttpTool) do
       description custom_tool_record.description
 
@@ -15,6 +18,16 @@ module Concerns::Toolable
       end
     end
 
+    # Register the dynamically created class as a constant in the Captain::Tools namespace.
+    # This is required because RubyLLM's Tool base class derives the tool name from the class name
+    # (via Class#name). Anonymous classes created with Class.new have no name and return empty strings,
+    # which causes "Invalid 'tools[].function.name': empty string" errors from the LLM API.
+    # By setting it as a constant, the class gets a proper name (e.g., "Captain::Tools::CatFactLookup")
+    # which RubyLLM extracts and normalizes to "cat-fact-lookup" for the LLM API.
+    # We refresh the constant on each call to ensure tool metadata changes are reflected.
+    Captain::Tools.send(:remove_const, class_name) if Captain::Tools.const_defined?(class_name, false)
+    Captain::Tools.const_set(class_name, tool_class)
+
     tool_class.new(assistant, self)
   end