Project folders for the agent, Local, the menu under its button

- Settings… lists the folders the agent may work in, with the system's
  folder dialog, remove, max mode and terminal, all through
  'lembas remote … --json' (CLI 1.2.0). Turning the agent on with no
  folder opens it; the title bar says 'agent: no folders' instead of green.
- The content webview's User-Agent carries LLeMbasDesktop/<v> (host=…),
  so the server can show this computer's device as Local.
- The title bar menu pops up at the button (popup_menu_at): Wayland gave
  the pointer-less popup the middle of the window.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src-tauri/src/remote.rs

@@ -0,0 +1,77 @@
+//! Which folders the agent may work in: the CLI's `remote` settings, read and changed through
+//! `lembas remote … --json` so the app never edits the CLI's files itself. A freshly linked
+//! computer allows no folder at all (remote control is off and `roots` is empty), so the agent
+//! is connected but every agent chat on it is refused until at least one folder is added.
+
+use std::process::{Command, Stdio};
+
+use serde::{Deserialize, Serialize};
+
+use crate::cli;
+
+/// `lembas remote list --json`, and what every changing command answers with.
+#[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq)]
+#[serde(default)]
+pub struct Remote {
+    pub enabled: bool,
+    pub roots: Vec<String>,
+    pub max_mode: String,
+    pub terminal: bool,
+    /// The running service must start again for the change to apply.
+    pub restart_needed: bool,
+}
+
+impl Remote {
+    /// Agent chats can be opened here at all.
+    pub fn usable(&self) -> bool {
+        self.enabled && !self.roots.is_empty()
+    }
+}
+
+/// Run `lembas remote <args…> --json`: the new state, or what the CLI said went wrong.
+pub fn run(args: &[&str]) -> Result<Remote, String> {
+    let out = Command::new(cli::binary())
+        .arg("remote")
+        .args(args)
+        .arg("--json")
+        .stdin(Stdio::null())
+        .output()
+        .map_err(|e| format!("Could not start {}: {e}", cli::binary().display()))?;
+    if !out.status.success() {
+        let err = String::from_utf8_lossy(&out.stderr).trim().to_string();
+        return Err(if err.is_empty() {
+            format!("lembas remote {} failed ({})", args.join(" "), out.status)
+        } else {
+            err.trim_start_matches("lembas: ").to_string()
+        });
+    }
+    parse(&String::from_utf8_lossy(&out.stdout))
+}
+
+/// The last JSON object the CLI printed (it may say a word before it).
+fn parse(stdout: &str) -> Result<Remote, String> {
+    stdout
+        .lines()
+        .rev()
+        .find_map(|l| serde_json::from_str::<Remote>(l.trim()).ok())
+        .ok_or_else(|| "lembas remote gave no answer this version of the app understands — is the bundled LLeMbas CLI too old?".to_string())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn reads_the_state_and_defaults_what_is_missing() {
+        let r = parse(
+            "added /home/a/project\n{\"enabled\":true,\"roots\":[\"/home/a/project\"],\"max_mode\":\"edit\",\"terminal\":false}\n",
+        )
+        .unwrap();
+        assert!(r.usable());
+        assert_eq!(r.roots, vec!["/home/a/project"]);
+        assert!(!r.restart_needed);
+        let off = parse("{\"enabled\":false,\"roots\":[]}").unwrap();
+        assert!(!off.usable());
+        assert!(parse("lembas: unknown command remote").is_err());
+    }
+}