TickSpec -> Expecto bridge. Feature files load from embedded resources in
 the CALLER's assembly and scenarios group by their Gherkin `Rule:` into
 nested test lists.

 Focus and pending are driven by Gherkin tags — TickSpec merges feature-
 and rule-level tags into every scenario's Tags, so the tag works at any
 level:
   @focus    -> Expecto Focused (only focused tests run; the rest report
                as skipped)
   @pending  -> Expecto Pending (never runs, reported as pending)
 A feature whose scenarios are ALL pending (e.g. one `@pending` above
 `Feature:`) is built from its parsed SOURCE without binding any steps, so
 a spec written ahead of its implementation joins the suite as pending
 scenarios instead of failing step binding. Scenario-level `@pending`
 still requires the feature's other steps to bind. The legacy `_` name
 prefix also focuses a feature or scenario.

 Every entry point takes the assembly holding the steps and feature
 resources explicitly. Resolving it here (GetExecutingAssembly) would bind
 to THIS library once it ships as a compiled package, silently scanning an
 assembly with no steps — pass your test assembly instead, typically
 `Assembly.GetExecutingAssembly()` at the call site.