Double check that you have no inherited view that remove `options` you
set on a field ! If nothing works, add a debugger in the first line of
`_search method` and enable debug mode in Odoo. When you write something
in a many2one field, javascript debugger should pause. If not verify
your installation.

- Instead of making the tags rectangle clickable, I think it's better to
  put the text as a clickable link, so we will get a consistent
  behaviour/aspect with other clickable elements (many2one...).