Add dotfiles management: push/pull/sync/diff/ls with KV-backed manifest

- New dotfiles subcommand with init, ls, push, pull, sync, diff
- Manifest-driven: maps KV paths to local filesystem per host
- Host aliasing (fuji-2 -> fuji) for flexible hostname matching
- Supports shared (cross-machine) and host-specific configs
- 13 files tracked: fish, starship, vim, kitty, git, zsh, skhd
- Bump to v0.2.0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@madcat-os/saiden-config",
-  "version": "0.1.5",
+  "version": "0.2.0",
   "type": "module",
   "bin": {
     "saiden-config": "bin/saiden-config.js"