feat(maestro): add the ctrl-k command bar to the TUI

Opens from Normal and Insert mode as an ordinary keymap entry, so it is
rebindable and the help overlay picks it up from the live keymap. An
empty query lists sessions most recently focused first, matching the web
bar's `orderSessionsForBar`; typing ranks through `matcher.rs` with the
matched ranges highlighted, grouped under kind headers.

Enter attaches through the same path the sidebar's attach uses, Escape
closes and leaves focus and mode where they were.

crates/maestro-protocol/src/display.rs

@@ -202,6 +202,41 @@ pub fn command_program(command: &str) -> String {
     }
 }
 
+/// Program name (already basenamed and lowercased) -> the tool id its mark
+/// stands for. Mirrors the web's `BY_PROGRAM` in `web/src/toolIcon.ts`;
+/// recognition is deliberately narrow, so an unrecognised program has no tool.
+const BY_PROGRAM: [(&str, &str); 17] = [
+    ("claude", "claude"),
+    ("claude-code", "claude"),
+    ("codex", "codex"),
+    ("opencode", "opencode"),
+    ("gemini", "gemini"),
+    ("aider", "aider"),
+    ("cursor", "cursor"),
+    ("cursor-agent", "cursor"),
+    ("pi", "pi"),
+    ("bash", "shell"),
+    ("zsh", "shell"),
+    ("sh", "shell"),
+    ("fish", "shell"),
+    ("dash", "shell"),
+    ("ksh", "shell"),
+    ("nu", "shell"),
+    ("xonsh", "shell"),
+];
+
+/// The tool id a command line's icon stands for (`claude`, `codex`,
+/// `opencode`, ...), or `None` when the program is not one we have a mark for.
+/// The command bar matches this field (`docs/COMMAND-BAR.md`), so it must name
+/// the same tools the web's `splitCommand().tool` does.
+pub fn command_tool(command: &str) -> Option<&'static str> {
+    let program = command_program(command).to_lowercase();
+    BY_PROGRAM
+        .iter()
+        .find(|(name, _)| *name == program)
+        .map(|(_, tool)| *tool)
+}
+
 /// `FOO=bar`, the shell's own prefix for one command's environment.
 fn is_env_assignment(word: &str) -> bool {
     let mut chars = word.chars();
@@ -476,4 +511,22 @@ mod tests {
         assert_eq!(command_program("sudo"), "sudo");
         assert_eq!(command_program(""), "");
     }
+
+    /// The command bar's `tool` field (docs/COMMAND-BAR.md) names the same
+    /// tools the web's `splitCommand().tool` does.
+    #[test]
+    fn command_tool_names_the_mark_the_card_shows() {
+        assert_eq!(command_tool("claude --resume"), Some("claude"));
+        assert_eq!(command_tool("npx opencode"), Some("opencode"));
+        assert_eq!(command_tool("/bin/zsh -l"), Some("shell"));
+        assert_eq!(command_tool("CLAUDE"), Some("claude"));
+    }
+
+    /// Narrow on purpose: an unrecognised program has no mark, so the
+    /// candidate has no `tool` field to match rather than a wrong one.
+    #[test]
+    fn command_tool_is_absent_for_an_unrecognised_program() {
+        assert_eq!(command_tool("hx src/main.rs"), None);
+        assert_eq!(command_tool(""), None);
+    }
 }