feat(tui)!: two transcript spacings, with spacious as the default

`comfortable` and `compact` rendered identically in a conversation: the
separator matrix gave `Compact | Comfortable` one arm at turn boundaries, and
only differed at Activity boundaries (0 vs 1 row). A setting that renders the
same as its neighbour is a lie in the settings list, so the ladder is now two
real levels.

- `compact`: 0 rows at activity seams, 1 at turn seams (unchanged).
- `spacious`: 2 at activity seams, 3 at turn seams. Previously 1 and 2, so
  this is roughly 1.6x the air it had.

`spacious` becomes the default. An existing `comfortable` (or `default`/
`normal`) value normalizes to `spacious`, and the schema declares only the two
live values so the picker cannot offer a setting that does nothing.

The transcript tests are updated from the 3-way matrix to assert both ladders
and to prove compact never spends a double blank. `history.rs` and the widget
test fixture move from Comfortable to Spacious.

NOT VERIFIED: no compile or test run. The workspace build lock was held by
another session for this entire slice (their `cargo check`/`cargo test`
cycles), and one native build per machine is the rule. Verified by inspection
only: the match in `spacer_rows_for_boundary` covers 4 boundaries x 2 spacings
exhaustively, and `settings_schema`'s
`enum_values_are_unique_and_defaults_are_declared_values` still holds because
`spacious` is a declared value.

crates/config/src/settings_schema.rs

@@ -346,6 +346,11 @@ const DENSITY: &[SettingOption] = &[
     SettingOption::new("spacious", "", ""),
 ];
 
+const TRANSCRIPT_SPACING: &[SettingOption] = &[
+    SettingOption::new("compact", "", ""),
+    SettingOption::new("spacious", "", ""),
+];
+
 const TOOL_COLLAPSE: &[SettingOption] = &[
     SettingOption::new("compact", "", ""),
     SettingOption::new("expanded", "", ""),
@@ -687,8 +692,8 @@ pub const SETTINGS_SCHEMA: &[SettingDef] = &[
     ),
     def(
         "transcript_spacing",
-        SettingKind::Enum(DENSITY),
-        "comfortable",
+        SettingKind::Enum(TRANSCRIPT_SPACING),
+        "spacious",
         ui(
             TAB_APPEARANCE,
             "display",

crates/tui/src/commands/config_main_host.rs

@@ -199,7 +199,6 @@ pub(crate) fn show_single_setting(app: &App, key: &str) -> ConfigReply {
     fn spacing_display(s: crate::tui::app::TranscriptSpacing) -> &'static str {
         match s {
             crate::tui::app::TranscriptSpacing::Compact => "compact",
-            crate::tui::app::TranscriptSpacing::Comfortable => "comfortable",
             crate::tui::app::TranscriptSpacing::Spacious => "spacious",
         }
     }

crates/tui/src/settings.rs

@@ -585,7 +585,7 @@ impl Default for Settings {
             composer_border: true,
             composer_multiline_mode: false,
             composer_vim_mode: "normal".to_string(),
-            transcript_spacing: "comfortable".to_string(),
+            transcript_spacing: "spacious".to_string(),
             default_mode: "agent".to_string(),
             sidebar_width_percent: 28,
             sidebar_focus: "auto".to_string(),
@@ -2885,7 +2885,7 @@ fn normalize_composer_density(value: &str) -> &str {
 fn normalize_transcript_spacing(value: &str) -> &str {
     match value.trim().to_ascii_lowercase().as_str() {
         "compact" | "tight" => "compact",
-        "comfortable" | "default" | "normal" => "comfortable",
+        "comfortable" | "default" | "normal" => "spacious",
         "spacious" | "loose" => "spacious",
         _ => value,
     }
@@ -3602,7 +3602,7 @@ mod tests {
             load_error: None,
             fancy_animations: true,
             show_tool_details: true,
-            transcript_spacing: "comfortable".to_string(),
+            transcript_spacing: "spacious".to_string(),
             ..Settings::default()
         }
     }
@@ -3634,13 +3634,13 @@ mod tests {
     }
 
     #[test]
-    fn default_settings_use_comfortable_transcript_spacing() {
+    fn default_settings_use_spacious_transcript_spacing() {
         let settings = Settings::default();
         assert!(settings.calm_mode);
         assert!(!settings.show_tool_details);
         assert!(!settings.low_motion);
         assert!(settings.fancy_animations);
-        assert_eq!(settings.transcript_spacing, "comfortable");
+        assert_eq!(settings.transcript_spacing, "spacious");
         assert_eq!(settings.tool_collapse_mode, "compact");
         // Thinking is opt-in so the transcript stays focused on the chat.
         assert!(!settings.show_thinking);
@@ -3859,7 +3859,7 @@ mod tests {
             "underwater presentation is the default"
         );
         assert!(!settings.low_motion);
-        assert_eq!(settings.transcript_spacing, "comfortable");
+        assert_eq!(settings.transcript_spacing, "spacious");
     }
 
     #[test]

crates/tui/src/tui/app/types.rs

@@ -120,7 +120,6 @@ impl ComposerDensity {
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum TranscriptSpacing {
     Compact,
-    Comfortable,
     Spacious,
 }
 
@@ -129,8 +128,7 @@ impl TranscriptSpacing {
     pub fn from_setting(value: &str) -> Self {
         match value.trim().to_ascii_lowercase().as_str() {
             "compact" | "tight" => Self::Compact,
-            "spacious" | "loose" => Self::Spacious,
-            _ => Self::Comfortable,
+            _ => Self::Spacious,
         }
     }
 }

crates/tui/src/tui/history.rs

@@ -269,7 +269,7 @@ impl Default for TranscriptRenderOptions {
             calm_mode: false,
             low_motion: false,
             motion_mode: MotionMode::Full,
-            spacing: TranscriptSpacing::Comfortable,
+            spacing: TranscriptSpacing::Spacious,
             palette_mode: palette::PaletteMode::detect(),
             prose_measure: None,
         }

crates/tui/src/tui/transcript.rs

@@ -1155,11 +1155,9 @@ const fn spacer_rows_for_boundary(
     match (boundary, spacing) {
         (TranscriptBoundary::Joined | TranscriptBoundary::GroupedTool, _) => 0,
         (TranscriptBoundary::Activity, TranscriptSpacing::Compact) => 0,
-        (TranscriptBoundary::Activity, _) => BLOCK_SEPARATOR_ROWS,
-        (TranscriptBoundary::Turn, TranscriptSpacing::Compact | TranscriptSpacing::Comfortable) => {
-            BLOCK_SEPARATOR_ROWS
-        }
-        (TranscriptBoundary::Turn, TranscriptSpacing::Spacious) => BLOCK_SEPARATOR_ROWS + 1,
+        (TranscriptBoundary::Activity, TranscriptSpacing::Spacious) => BLOCK_SEPARATOR_ROWS + 1,
+        (TranscriptBoundary::Turn, TranscriptSpacing::Compact) => BLOCK_SEPARATOR_ROWS,
+        (TranscriptBoundary::Turn, TranscriptSpacing::Spacious) => BLOCK_SEPARATOR_ROWS + 2,
     }
 }
 

crates/tui/src/tui/transcript/tests.rs

@@ -764,36 +764,23 @@ fn semantic_boundary_matrix_has_four_deliberate_rhythm_levels() {
         spacer_rows_for_boundary(Turn, TranscriptSpacing::Compact),
         1
     );
-    assert_eq!(
-        spacer_rows_for_boundary(Turn, TranscriptSpacing::Comfortable),
-        1
-    );
     assert_eq!(
         spacer_rows_for_boundary(Turn, TranscriptSpacing::Spacious),
-        2
+        3
     );
     assert_eq!(
         spacer_rows_for_boundary(Activity, TranscriptSpacing::Compact),
         0
     );
-    assert_eq!(
-        spacer_rows_for_boundary(Activity, TranscriptSpacing::Comfortable),
-        1
-    );
     assert_eq!(
         spacer_rows_for_boundary(Activity, TranscriptSpacing::Spacious),
-        1
+        2
     );
     assert_eq!(
         spacer_rows_for_boundary(GroupedTool, TranscriptSpacing::Compact),
         0,
         "compact density buys its density by spending no separator rows"
     );
-    assert_eq!(
-        spacer_rows_for_boundary(GroupedTool, TranscriptSpacing::Comfortable),
-        0,
-        "the shared rail carries grouping without a row per tool call"
-    );
     assert_eq!(
         spacer_rows_for_boundary(GroupedTool, TranscriptSpacing::Spacious),
         0,
@@ -801,29 +788,18 @@ fn semantic_boundary_matrix_has_four_deliberate_rhythm_levels() {
     );
 }
 
-/// Separation is one row or none. Nothing in the matrix may produce a
-/// double blank, because a scrolling terminal cannot afford it.
+/// Compact never spends a double blank, because a scrolling terminal cannot
+/// afford it. Spacious buys its air at turn and activity seams by design.
 #[test]
-fn no_boundary_ever_spends_more_than_one_row_below_spacious_turns() {
+fn compact_never_spends_more_than_one_row_at_any_boundary() {
     use TranscriptBoundary::{Activity, GroupedTool, Joined, Turn};
 
     for boundary in [Joined, GroupedTool, Activity, Turn] {
-        for spacing in [
-            TranscriptSpacing::Compact,
-            TranscriptSpacing::Comfortable,
-            TranscriptSpacing::Spacious,
-        ] {
-            let rows = spacer_rows_for_boundary(boundary, spacing);
-            let allowed = if boundary == Turn && spacing == TranscriptSpacing::Spacious {
-                2
-            } else {
-                BLOCK_SEPARATOR_ROWS
-            };
-            assert!(
-                rows <= allowed,
-                "{boundary:?} at {spacing:?} spent {rows} rows (max {allowed})"
-            );
-        }
+        let rows = spacer_rows_for_boundary(boundary, TranscriptSpacing::Compact);
+        assert!(
+            rows <= BLOCK_SEPARATOR_ROWS,
+            "{boundary:?} at compact spent {rows} rows"
+        );
     }
 }
 
@@ -908,26 +884,26 @@ fn durable_work_starts_a_new_activity_rail_without_wasting_compact_rows() {
         "durable Work should open its own rail: {durable_work:?}"
     );
 
-    let mut comfortable = TranscriptViewCache::new();
-    comfortable.ensure(
+    let mut spacious = TranscriptViewCache::new();
+    spacious.ensure(
         &cells,
         &revisions,
         80,
         TranscriptRenderOptions {
-            spacing: TranscriptSpacing::Comfortable,
+            spacing: TranscriptSpacing::Spacious,
             low_motion: true,
             ..TranscriptRenderOptions::default()
         },
     );
     assert_eq!(
-        spacer_rows_after_cell(&comfortable, 0),
+        spacer_rows_after_cell(&spacious, 0),
         0,
         "two commands inside one activity rail must remain compact"
     );
     assert_eq!(
-        spacer_rows_after_cell(&comfortable, 1),
-        1,
-        "durable Work needs a semantic activity row outside compact density"
+        spacer_rows_after_cell(&spacious, 1),
+        2,
+        "durable Work needs a semantic activity break outside compact density"
     );
 }
 
@@ -1092,30 +1068,38 @@ fn transcript_rhythm_is_width_and_reduced_motion_invariant() {
     ];
     let revisions = vec![1u64; cells.len()];
     // user | reasoning | answer | tool | work | answer | user.
-    // Every seam is one row: the reasoning→answer seam (index 1) used to be
-    // the one place the transcript ran two blocks together.
-    let expected = [1, 1, 1, 1, 1, 1, 0];
+    // Turn seams breathe widest; activity seams are the interior of one turn.
+    let expected_compact = [1, 0, 0, 0, 0, 1, 0];
+    let expected_spacious = [3, 2, 2, 2, 2, 3, 0];
 
     for width in [40, 80, 100, 140] {
         for low_motion in [false, true] {
-            let options = TranscriptRenderOptions {
-                low_motion,
-                spacing: TranscriptSpacing::Comfortable,
-                ..TranscriptRenderOptions::default()
-            };
-            let mut cache = TranscriptViewCache::new();
-            cache.ensure(&cells, &revisions, width, options);
+            for (spacing, expected) in [
+                (TranscriptSpacing::Compact, expected_compact),
+                (TranscriptSpacing::Spacious, expected_spacious),
+            ] {
+                let options = TranscriptRenderOptions {
+                    low_motion,
+                    spacing,
+                    ..TranscriptRenderOptions::default()
+                };
+                let mut cache = TranscriptViewCache::new();
+                cache.ensure(&cells, &revisions, width, options);
 
-            let actual =
-                std::array::from_fn::<_, 7, _>(|index| spacer_rows_after_cell(&cache, index));
-            assert_eq!(actual, expected, "width={width} low_motion={low_motion}");
-            assert!(
-                cache
-                    .lines()
-                    .iter()
-                    .all(|line| line.width() <= usize::from(width)),
-                "render exceeded width={width} low_motion={low_motion}"
-            );
+                let actual =
+                    std::array::from_fn::<_, 7, _>(|index| spacer_rows_after_cell(&cache, index));
+                assert_eq!(
+                    actual, expected,
+                    "width={width} low_motion={low_motion} spacing={spacing:?}"
+                );
+                assert!(
+                    cache
+                        .lines()
+                        .iter()
+                        .all(|line| line.width() <= usize::from(width)),
+                    "render exceeded width={width} low_motion={low_motion}"
+                );
+            }
         }
     }
 }
@@ -2636,11 +2620,8 @@ impl TranscriptModel {
                 "width"
             }
             11 => {
-                self.options.spacing = [
-                    TranscriptSpacing::Compact,
-                    TranscriptSpacing::Comfortable,
-                    TranscriptSpacing::Spacious,
-                ][rng.below(3)];
+                self.options.spacing =
+                    [TranscriptSpacing::Compact, TranscriptSpacing::Spacious][rng.below(2)];
                 self.options.show_thinking = rng.below(4) != 0;
                 "options"
             }

crates/tui/src/tui/widgets/mod.rs

@@ -3950,7 +3950,7 @@ mod tests {
             let mut app = create_test_app();
             app.low_motion = true;
             app.fancy_animations = false;
-            app.transcript_spacing = TranscriptSpacing::Comfortable;
+            app.transcript_spacing = TranscriptSpacing::Spacious;
 
             for turn in 0..4 {
                 app.add_message(HistoryCell::User {