rewrite uberspace-cli in rust (phase 1 + 2)

single binary `uc` replaces bash asteroids script, unifies v7/v8
behind a stable interface with TOML config. implements registry CRUD,
SSH passthrough with v7/v8 translation, status collection/caching,
legacy import. 24 unit tests pass.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/ssh.rs

@@ -0,0 +1,58 @@
+use std::process::Command;
+
+use crate::registry::Asteroid;
+
+/// Run `ssh -t <name>@<server> uberspace <args...>` and inherit stdio.
+/// Returns the exit code from ssh.
+pub fn passthrough(asteroid: &Asteroid, args: &[String]) -> Result<i32, String> {
+	let host = format!("{}@{}", asteroid.name, asteroid.server);
+
+	let mut cmd = Command::new("ssh");
+	cmd.arg("-t").arg("-o").arg("BatchMode=no").arg(&host);
+	cmd.arg("uberspace");
+	cmd.args(args);
+
+	let status = cmd
+		.status()
+		.map_err(|e| format!("failed to execute ssh: {e}"))?;
+
+	Ok(status.code().unwrap_or(1))
+}
+
+/// Run a command on the remote via SSH and capture stdout.
+/// Used for status collection where we need to parse output.
+pub fn capture(asteroid: &Asteroid, remote_script: &str) -> Result<String, String> {
+	let host = format!("{}@{}", asteroid.name, asteroid.server);
+
+	let output = Command::new("ssh")
+		.arg("-o")
+		.arg("BatchMode=no")
+		.arg(&host)
+		.arg("bash")
+		.arg("-s")
+		.arg(asteroid.version.to_string())
+		.stdin(std::process::Stdio::piped())
+		.stdout(std::process::Stdio::piped())
+		.stderr(std::process::Stdio::inherit())
+		.spawn()
+		.and_then(|mut child| {
+			use std::io::Write;
+			if let Some(ref mut stdin) = child.stdin {
+				stdin.write_all(remote_script.as_bytes())?;
+			}
+			child.wait_with_output()
+		})
+		.map_err(|e| format!("ssh to {} failed: {e}", asteroid.name))?;
+
+	if !output.status.success() {
+		return Err(format!(
+			"ssh to {}@{} failed with exit code {}",
+			asteroid.name,
+			asteroid.server,
+			output.status.code().unwrap_or(1)
+		));
+	}
+
+	String::from_utf8(output.stdout)
+		.map_err(|e| format!("invalid utf-8 from ssh output: {e}"))
+}