chore(release): prepare v1.0.1 — window position recovery

Bumps version to 1.0.1.0 and aligns the user-facing changelog across
HellionChat.csproj, HellionChat.yaml, repo.json and docs/CHANGELOG.md.

Headline fix: off-screen window recovery (one-shot bounds check on
plugin load + manual reset button under Settings -> Window -> Frame).
Bundled housekeeping since v1.0.0: docs restructured into docs/, stale
ChatTwo/* paths cleaned up across configs, Pidgin 3.3.0 -> 3.5.1,
actions/setup-dotnet 4 -> 5, github/codeql-action 3 -> 4.

DLL build verified locally; release.yml workflow generates the release
body from HellionChat.yaml on tag push.

HellionChat/HellionChat.csproj

@@ -4,7 +4,7 @@
              0.1.0 is our bootstrap release; the underlying Chat 2 base is
              called out in the yaml changelog so users can see what it
              derives from. -->
-        <Version>1.0.0</Version>
+        <Version>1.0.1</Version>
         <ImplicitUsings>enable</ImplicitUsings>
         <!-- Honor packages.lock.json on restore so floating version ranges
              don't silently drift between machines or CI runs. -->