feat(init): add Codex CLI init support via AGENTS.md + RTK.md

hooks/rtk-awareness-codex.md

@@ -0,0 +1,32 @@
+# RTK - Rust Token Killer (Codex CLI)
+
+**Usage**: Token-optimized CLI proxy for shell commands.
+
+## Rule
+
+Always prefix shell commands with `rtk`.
+
+Examples:
+
+```bash
+rtk git status
+rtk cargo test
+rtk npm run build
+rtk pytest -q
+```
+
+## Meta Commands
+
+```bash
+rtk gain            # Token savings analytics
+rtk gain --history  # Recent command savings history
+rtk proxy <cmd>     # Run raw command without filtering
+```
+
+## Verification
+
+```bash
+rtk --version
+rtk gain
+which rtk
+```