refactor: use michaotic username throughout, add cli/kitty/zsh configs and docs

garden.md

@@ -24,9 +24,21 @@ Hosts in this repo are named after plants and flowers.
 - `hosts/<name>/default.nix` — per-host config
 - `hosts/common/default.nix` — shared NixOS config
 - `hosts/common-darwin/default.nix` — shared darwin config
-- `home/default.nix` — shared home-manager config for user `mikl`
+- `home/default.nix` — shared home-manager config for user `michaotic` (plan to migrate to `mikl` later)
 - `secrets/` — sops-encrypted secrets per host
 
 ## migrations
 
-- `nix-config-legacy/` — previous muscari-only config (preserved for reference)
+- `nix-config-legacy/` — previous muscari-only config (preserved for reference)
+
+## future plans
+
+### username migration
+
+currently using `michaotic` as username (historical). plan to migrate to `mikl` across all hosts for consistency.
+
+**why not now:**
+- macOS: changing username requires careful handling of home folder, keychain, permissions
+- linux: easier, but better to do in one coordinated change
+
+**when:** after setting up proper backups and testing migration procedure