feat(maestro): add elicitation web UI and TUI stub

ElicitationView renders form-mode questions from the agent:
single-property string enums as a button group (the common
multiple-choice case), general schemas as a form with typed
inputs.

Wired into TranscriptRow, StructuredPane, and the model
helpers. TUI renders elicitation rows as plain text for now.

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

crates/maestro-tui/src/structured_pane.rs

@@ -355,6 +355,15 @@ fn build_lines(state: &StructuredState, width: usize) -> Vec<VisualLine> {
                 Tone::Muted,
                 false,
             ),
+            TranscriptRowKind::Elicitation => push_wrapped(
+                &mut out,
+                row,
+                "? ",
+                content_text(row),
+                row_width,
+                Tone::Muted,
+                false,
+            ),
             TranscriptRowKind::Plan => {}
         }
         if out.len() > start
@@ -399,6 +408,7 @@ pub fn copy_text(row: &TranscriptRow) -> String {
             .and_then(serde_json::Value::as_str)
             .unwrap_or("permission requested")
             .into(),
+        TranscriptRowKind::Elicitation => content_text(row),
         TranscriptRowKind::Notice => "[notice]".into(),
         TranscriptRowKind::Plan => String::new(),
     }