Update to version v0.1.2.a.6 and enhance plugin security in terminal.py

- Updated index.html and version.txt to reflect the new release version v0.1.2.a.6.
- Introduced security measures for plugin loading in terminal.py, including AST validation and quarantine for unsafe plugins.
- Added a safe mode option to prevent plugin loading, enhancing overall security.

index.html

@@ -46,7 +46,7 @@
     <div class="hero__metrics">
       <div class="metric">
         <p class="metric__label">Current release</p>
-        <p class="metric__value">v0.1.2.a.5</p>
+        <p class="metric__value">v0.1.2.a.6</p>
       </div>
       <div class="metric">
         <p class="metric__label">Supported families</p>