Stop tracking local.env and .claude

local.env carries the database password and the provider key of whoever runs the
service: it is one person's machine, not the project. .claude/settings.json is the
same kind of thing, a local tool's permission list. Both stay on disk and are now
ignored.

This removes them from future commits only. Their contents remain in the history
that is already on origin, so the credentials they held must be treated as known
to everyone with access to the repository.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.gitignore

@@ -36,3 +36,8 @@ build/
 
 ### macOS ###
 .DS_Store
+
+### Local environment and tooling ###
+# Holds DB and provider credentials: never tracked.
+local.env
+.claude/