fix(tui): theme the AI plan popup's highlight, help, and pending markers (#169)

* fix(tui): theme the AI plan popup's highlight, help, and pending markers

The AI plan overlay already filled its interior with the theme background, but
the selected step was drawn with a hardcoded magenta bar and the help line and
pending-step markers with a hardcoded gray — jarring on non-default themes (e.g.
mc's blue). The highlighted step now uses the theme's selection colors (like the
panes), and the help + pending markers use the theme's status color. Approval/run
status keeps its semantic colors (green/red/cyan).

Test asserts the overlay carries the theme background, the highlighted step uses
the theme selection colour, and no hardcoded magenta highlight remains. Snapshots
are unaffected (they capture glyphs, not colour).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* test(tui): assert the AI overlay's help/pending markers use theme.status

Review follow-up: the theming test only covered the highlight color. Override
theme.status to a distinctive value and assert both a pending step's marker and
the help line render with it, so the help/pending half of the fix has regression
protection too.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: zoza1982

CHANGELOG.md

@@ -182,6 +182,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- **The AI plan popup now matches the active theme.** The overlay already used the theme background,
+  but the selected step was drawn with a hardcoded magenta bar and the help/pending markers with a
+  hardcoded gray — jarring on non-default themes. The highlighted step now uses the theme's selection
+  colors (like the panes), and the help line and pending markers use the theme's status color.
+  Approval/run status keeps its semantic colors (green approved, red rejected/failed, cyan done).
+
 - **A large copy/move no longer stalls on the pre-flight size scan.** The scan that sizes the source
   tree for a percentage/ETA is now **time-boxed** (≤ 0.8 s) and **entry-capped** — so copying a huge
   or remote (SFTP) folder starts almost immediately with an indeterminate, animated bar (MC-style)

crates/cairn-tui/src/render.rs

@@ -1333,8 +1333,11 @@ fn render_ai_plan(frame: &mut Frame, plan: &Plan, cursor: usize, theme: &Theme)
         .steps
         .iter()
         .map(|s| {
+            // Approval/run status keeps its semantic colors (green approved, red rejected/failed,
+            // cyan done); a still-pending step uses the theme's status color so it doesn't clash on a
+            // non-default theme (it was a hardcoded gray).
             let (marker, color) = match s.status {
-                StepStatus::Pending => ('·', Color::Gray),
+                StepStatus::Pending => ('·', theme.status),
                 StepStatus::Approved => ('✓', Color::Green),
                 StepStatus::Rejected => ('✗', Color::Red),
                 StepStatus::Done => ('●', Color::Cyan),
@@ -1354,7 +1357,13 @@ fn render_ai_plan(frame: &mut Frame, plan: &Plan, cursor: usize, theme: &Theme)
         })
         .collect();
     let list = List::new(items)
-        .highlight_style(Style::default().bg(Color::Magenta).fg(Color::Black))
+        // Use the theme's selection colors (like the panes) instead of a hardcoded magenta bar, so
+        // the highlighted step matches the active theme.
+        .highlight_style(
+            Style::default()
+                .bg(theme.selection_bg)
+                .fg(theme.selection_fg),
+        )
         .highlight_symbol("▶ ");
     let mut list_state = ListState::default();
     if !plan.steps.is_empty() {
@@ -1368,7 +1377,7 @@ fn render_ai_plan(frame: &mut Frame, plan: &Plan, cursor: usize, theme: &Theme)
         "↵ approve · x reject · esc abort · no bulk (irreversible)"
     };
     frame.render_widget(
-        Paragraph::new(Line::from(help)).style(Style::default().fg(Color::Gray)),
+        Paragraph::new(Line::from(help)).style(Style::default().fg(theme.status)),
         help_area,
     );
 }
@@ -2341,6 +2350,85 @@ mod tests {
         assert!(changed, "themed background must paint at least one cell");
     }
 
+    #[test]
+    fn ai_plan_overlay_matches_the_theme() {
+        use cairn_ai::{capability_for, Plan, PlanState, PlanStep, StepStatus};
+        let steps = ["list", "copy"]
+            .iter()
+            .filter_map(|t| {
+                Some(PlanStep {
+                    tool: (*t).to_owned(),
+                    input: serde_json::Value::Null,
+                    description: format!("{t} the things"),
+                    capability: capability_for(t)?,
+                    status: StepStatus::Pending,
+                    error: None,
+                    output: None,
+                })
+            })
+            .collect();
+        let plan = Plan {
+            summary: "s".to_owned(),
+            steps,
+            state: PlanState::Proposed,
+        };
+        let mut s = ready_state();
+        s.overlay = Some(cairn_core::Overlay::AiPlan { plan, cursor: 0 });
+        // Distinctive theme colors so each role is distinguishable from the DARK defaults.
+        let status = Color::Rgb(1, 2, 3);
+        let theme = Theme {
+            background: Some(Color::Blue),
+            selection_bg: Color::Green,
+            selection_fg: Color::Black,
+            status,
+            ..Theme::DARK
+        };
+        let mut terminal = Terminal::new(TestBackend::new(80, 24)).unwrap();
+        terminal.draw(|f| render(f, &s, &theme)).unwrap();
+        let buf = terminal.backend().buffer().clone();
+        let width = usize::from(buf.area().width);
+        let mut saw_title_bg = false;
+        let mut highlight_is_theme = false;
+        let mut pending_is_status = false;
+        let mut help_is_status = false;
+        let mut any_magenta = false;
+        for row in buf.content().chunks(width) {
+            let text: String = row.iter().map(|c| c.symbol()).collect();
+            if text.contains("AI plan") {
+                saw_title_bg = row.iter().any(|c| c.style().bg == Some(Color::Blue));
+            }
+            if text.contains("list the things") {
+                // The highlighted step must use the theme selection bg, never a hardcoded magenta.
+                highlight_is_theme = row.iter().any(|c| c.style().bg == Some(Color::Green));
+            }
+            if text.contains("copy the things") {
+                // A non-highlighted pending step's marker uses the theme status color (was gray).
+                pending_is_status = row.iter().any(|c| c.style().fg == Some(status));
+            }
+            if text.contains("approve") {
+                // The help line uses the theme status color (was gray).
+                help_is_status = row.iter().any(|c| c.style().fg == Some(status));
+            }
+            if row.iter().any(|c| c.style().bg == Some(Color::Magenta)) {
+                any_magenta = true;
+            }
+        }
+        assert!(
+            saw_title_bg,
+            "the AI overlay's interior carries the theme background"
+        );
+        assert!(
+            highlight_is_theme,
+            "the highlighted step uses the theme selection colour"
+        );
+        assert!(
+            pending_is_status,
+            "a pending step's marker uses the theme status colour"
+        );
+        assert!(help_is_status, "the help line uses the theme status colour");
+        assert!(!any_magenta, "no hardcoded magenta highlight remains");
+    }
+
     #[test]
     fn overlays_pick_up_the_theme_background() {
         // A dialog must match the active theme, not the terminal default that its `Clear` would leave.