fix(completion): offer unique hostnames without instance prefix

bash (and zsh without a matcher) only accept candidates that start with
the typed text, so "fsn1-bx1<Tab>" found nothing when every candidate
was qualified as "prod/…". Hostnames that exist in only one instance
are now offered bare; names present in several instances stay
qualified. Connecting to a bare name still checks every instance for
ambiguity, so the connection behavior is unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## v0.0.22
+
+- Fix shell completion with multiple NetBox instances: typing a hostname without an instance prefix (`fsn1-bx1<Tab>`) found nothing in bash and zsh, because only `prod/…` was offered. Hostnames that are unique across all instances are now offered without the prefix; connecting to them still checks every instance for ambiguous names.
+- zsh also accepts instance-qualified matches for the typed hostname, so names that exist in several instances are offered as `prod/…` and `stg/…`.
+
 ## v0.0.21
 
 - Ship a zsh completion script built for large caches: 5000 hosts complete in under 0.1 s instead of hanging for seconds with Cobra's generated script.