Do not execute previously executed filters

If an action is to apply a tag, we should implicitly include automatically generated filters applying a `__not` so we don't run an action needlessly and prevent conf.yaml creep. xref #9

Start by reading the related issue #9 and locating the implementation of actions that apply tags and automatically generated filters. Trace how previously executed filters are represented, then verify that a tag action skips matching prior filters and avoids unnecessary conf.yaml entries.

Written by the indexing model from the issue text.