chore(claude): permissive project settings + gitignore local file

Team-wide Claude Code permissions for the dev workflows actually
used in this repo (cargo, npm, docker, psql, curl, git, gh, jq,
exploration commands, common env-var prefixes), plus a targeted
denylist for the destructive operations that warrant explicit
confirmation (force-push, push to main, branch -D, docker prune
variants, rm -rf outside the project tree, sudo / passwd / dd).

  * .claude/settings.json — checked-in team-wide config
    (125 allow rules, 55 deny rules)
  * .claude/settings.local.json — gitignored, kept as the
    holding pen for personal in-session grants
  * .gitignore — adds the .local.json exclusion

The permissive shape is "allow everything common, deny the
specifically destructive." Mid-pattern wildcards in Bash rules
aren't actually supported by the matcher; the deny list only
uses prefix patterns that the engine respects.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -10,6 +10,10 @@ Cargo.lock.bak
 *.swo
 .DS_Store
 
+# Claude Code — team-wide settings go in .claude/settings.json (tracked);
+# personal grants from in-session prompts live in settings.local.json.
+.claude/settings.local.json
+
 # Env / secrets
 .env
 .env.*