Add AI profiles and harness adapters (claude-code, codex, opencode, native)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QKxGW1raAWaqeU8WdHsMsp

bin/omarchy-cn-ai-profile-use

@@ -0,0 +1,19 @@
+#!/bin/bash
+# omarchy:summary=Set the default AI profile
+# omarchy:args=<name>
+# omarchy:examples=omarchycn ai profile use work
+
+set -euo pipefail
+
+source "$OMARCHY_PATH/cn/lib/ai.sh"
+
+name="${1:?usage: omarchycn ai profile use <name>}"
+
+if [[ ! -f $CN_AI_PROFILE_DIR/$name.toml ]]; then
+  echo "No such profile: $name (see: omarchycn ai profile list)" >&2
+  exit 1
+fi
+
+mkdir -p "${CN_AI_CURRENT%/*}"
+echo "$name" > "$CN_AI_CURRENT"
+echo "Default AI profile: $name"