Do not enable debug tools for lib templates (#45)

## Problem statement 

When using `reactionview` with the `intercept_erb` and `debug` options,
one can get warnings for templates that are outside one's control.

Here's an example with the [Avo ](https://github.com/avo-hq/avo)
dashboard in one of my apps:

<img width="2726" height="1776" alt="CleanShot 2025-10-10 at 15 37
01@2x"
src="https://github.com/user-attachments/assets/0b4905ce-c338-4254-af1d-e84b06764418"
/>

The problem has also been described in
#43

## Proposed solution

The proposed change here only allows debug for "local" templates, i.e.
templates rendered from the main app `app/views` directory.

## Potential shortcomings 

The solution proposed only works for templates inside
`"#{Rails.root}/app/views"`.
It means that should an app use local engines, the engine templates will
not benefit from ReActionView debug tools.

One potential solution would be to add a new configuration item that
would basically be an allow-list for other template paths within the
app.

Resolves #43

Author: virolea

lib/reactionview/template/handlers/herb.rb

@@ -11,7 +11,7 @@ class Herb < ActionView::Template::Handlers::ERB
         def call(template, source)
           visitors = []
 
-          if ::ReActionView.config.debug_mode_enabled?
+          if ::ReActionView.config.debug_mode_enabled? && local_template?(template)
             visitors << ::Herb::Engine::DebugVisitor.new(
               file_path: template.identifier,
               project_path: Rails.root.to_s
@@ -37,8 +37,15 @@ def layout_template?(template)
           template.identifier.include?("/layouts/")
         end
 
+        def local_template?(template)
+          return true unless template.respond_to?(:identifier) && template.identifier
+
+          template.identifier.start_with?("#{Rails.root}/app/views")
+        end
+
         def reactionview_dev_tools_markup(template)
           return nil unless layout_template?(template) && ::ReActionView.config.debug_mode_enabled?
+          return nil unless local_template?(template)
 
           <<~HTML
             <meta name="herb-debug-mode" content="true">