Add server install verification steps

INSTALL.md

@@ -0,0 +1,24 @@
+# Install mim on an SSH server
+
+`mim` is installed by copying one named local build profile to a server-side `bin/mim` path. There is no package manager integration, runtime config, plugin installer, or hidden bootstrap step.
+
+From a clean checkout on the target server:
+
+```sh
+zig build install-code --prefix "$HOME/.local"
+"$HOME/.local/bin/mim" --version
+```
+
+Choose the smallest profile that matches the server job:
+
+- `zig build install-min --prefix "$HOME/.local"` installs `mim-min` as `$HOME/.local/bin/mim`.
+- `zig build install-code --prefix "$HOME/.local"` installs `mim-code` as `$HOME/.local/bin/mim`.
+- `zig build install-full --prefix "$HOME/.local"` installs `mim-full` as `$HOME/.local/bin/mim`.
+
+For CI or agent verification without relying on the shell to execute the copied path directly, use the matching verification step:
+
+```sh
+zig build verify-install-code --prefix /tmp/mim-install
+```
+
+That step installs the selected binary to `/tmp/mim-install/bin/mim` and runs the installed artifact with `--version`.