Add portable Claude Code config

Saves ~/.claude/settings.json (user-level prefs + Bash/Read permissions
allowlist) so the same Claude Code config can be replicated on other
hosts via install.sh.

What gets deployed:
- .claude/settings.json — theme, verbose, defaultMode, skipAutoPermissionPrompt
  and the cumulative "approve once" allowlist for common ops (systemctl,
  iptables, journalctl, git, curl, etc.). Server-specific allow entries
  (e.g. /home/mastodon/* paths) are dead weight elsewhere but harmless.
- .claude/.gitignore — explicit deny-list so a future `git add .claude`
  doesn't accidentally pull in credentials, session logs, project
  memories, file-history, telemetry, caches, or settings.local.json.

What is NOT tracked (by design):
- .credentials.json (auth)
- history.jsonl, sessions/, projects/ (chat data, project memories)
- settings.local.json (per-machine overrides — by Claude Code convention)
- file-history/, plans/, paste-cache/, shell-snapshots/, session-env/,
  telemetry/, downloads/, cache/, backups/, mcp-needs-auth-cache.json
- plugins/ (marketplace install paths are absolute and host-specific)

deploy_dir's merge semantics mean: on a host that already has
~/.claude/.credentials.json or ~/.claude/projects/, those stay untouched
because the repo doesn't track them. Only the files we explicitly
include get installed.

Existing settings.json on the target host is moved aside to
~/.drunkendotfiles.bak.<timestamp>/ before being replaced.

install.sh

@@ -36,7 +36,7 @@ PERSONAL_FILES=(
 # untouched. This deliberately avoids wholesale-replacing $HOME/.local etc.,
 # which would sweep away unrelated user data (fonts, app state, ...).
 PERSONAL_DIRS=(
-  .fonts .irssi .nano .themes .local .mplayer
+  .fonts .irssi .nano .themes .local .mplayer .claude
 )
 
 have() { command -v "$1" >/dev/null 2>&1; }