diff --git a/src/command/cmd.rs b/src/command/cmd.rs
index d47d1c8..b4bdbbd 100644
--- a/src/command/cmd.rs
+++ b/src/command/cmd.rs
@@ -1602,7 +1602,11 @@ impl Cmd for TileAxisOp {
                 None => Box::new(effect::CycleAxis(name.to_string())),
             };
             let status = format!("{} → {}", name, axis_label(new_axis));
-            vec![axis_effect, effect::mark_dirty(), effect::set_status(status)]
+            vec![
+                axis_effect,
+                effect::mark_dirty(),
+                effect::set_status(status),
+            ]
         } else {
             vec![]
         }
@@ -2250,10 +2254,7 @@ effect_cmd!(
     "help",
     |_args: &[String]| -> Result<(), String> { Ok(()) },
     |_args: &Vec<String>, _ctx: &CmdContext| -> Vec<Box<dyn Effect>> {
-        vec![
-            effect::help_page_set(0),
-            effect::change_mode(AppMode::Help),
-        ]
+        vec![effect::help_page_set(0), effect::change_mode(AppMode::Help)]
     }
 );
 
@@ -3425,7 +3426,10 @@ mod tests {
         let effects = TransposeAxes.execute(&ctx);
         assert_eq!(effects.len(), 2);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("TransposeAxes"), "Expected TransposeAxes, got: {dbg}");
+        assert!(
+            dbg.contains("TransposeAxes"),
+            "Expected TransposeAxes, got: {dbg}"
+        );
     }
 
     // ── View navigation ────────────────────────────────────────────────
@@ -3439,7 +3443,10 @@ mod tests {
         let cmd = ViewNavigate { forward: true };
         let effects = cmd.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("No forward view"), "Expected status message, got: {dbg}");
+        assert!(
+            dbg.contains("No forward view"),
+            "Expected status message, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3451,7 +3458,10 @@ mod tests {
         let cmd = ViewNavigate { forward: false };
         let effects = cmd.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("No previous view"), "Expected status message, got: {dbg}");
+        assert!(
+            dbg.contains("No previous view"),
+            "Expected status message, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3465,7 +3475,10 @@ mod tests {
         let cmd = ViewNavigate { forward: true };
         let effects = cmd.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("ViewForward"), "Expected ViewForward, got: {dbg}");
+        assert!(
+            dbg.contains("ViewForward"),
+            "Expected ViewForward, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3480,7 +3493,10 @@ mod tests {
         let effects = cmd.execute(&ctx);
         assert_eq!(effects.len(), 2); // ApplyAndClearDrill + ViewBack
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("ApplyAndClearDrill"), "Expected ApplyAndClearDrill, got: {dbg}");
+        assert!(
+            dbg.contains("ApplyAndClearDrill"),
+            "Expected ApplyAndClearDrill, got: {dbg}"
+        );
         assert!(dbg.contains("ViewBack"), "Expected ViewBack, got: {dbg}");
     }
 
@@ -3501,7 +3517,10 @@ mod tests {
         let effects = cmd.execute(&ctx);
         assert_eq!(effects.len(), 1);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("SetPanelCursor"), "Expected SetPanelCursor, got: {dbg}");
+        assert!(
+            dbg.contains("SetPanelCursor"),
+            "Expected SetPanelCursor, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3588,7 +3607,10 @@ mod tests {
         // Should produce SetPageSelection effects
         assert!(!effects.is_empty());
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("SetPageSelection"), "Expected SetPageSelection, got: {dbg}");
+        assert!(
+            dbg.contains("SetPageSelection"),
+            "Expected SetPageSelection, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3600,7 +3622,10 @@ mod tests {
         let effects = PagePrev.execute(&ctx);
         assert!(!effects.is_empty());
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("SetPageSelection"), "Expected SetPageSelection, got: {dbg}");
+        assert!(
+            dbg.contains("SetPageSelection"),
+            "Expected SetPageSelection, got: {dbg}"
+        );
     }
 
     // ── Tile axis commands ─────────────────────────────────────────────
@@ -3657,7 +3682,10 @@ mod tests {
         let effects = cmd.execute(&ctx);
         assert_eq!(effects.len(), 1);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("SetTileCatIdx(1)"), "Expected idx 1, got: {dbg}");
+        assert!(
+            dbg.contains("SetTileCatIdx(1)"),
+            "Expected idx 1, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3670,7 +3698,10 @@ mod tests {
         let effects = cmd.execute(&ctx);
         assert_eq!(effects.len(), 1);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("SetTileCatIdx(0)"), "Expected clamped to 0, got: {dbg}");
+        assert!(
+            dbg.contains("SetTileCatIdx(0)"),
+            "Expected clamped to 0, got: {dbg}"
+        );
     }
 
     // ── Commit formula ─────────────────────────────────────────────────
@@ -3686,8 +3717,14 @@ mod tests {
         ctx.buffers = &bufs;
         let effects = CommitFormula.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("AddFormula"), "Expected AddFormula, got: {dbg}");
-        assert!(dbg.contains("FormulaPanel"), "Expected return to FormulaPanel, got: {dbg}");
+        assert!(
+            dbg.contains("AddFormula"),
+            "Expected AddFormula, got: {dbg}"
+        );
+        assert!(
+            dbg.contains("FormulaPanel"),
+            "Expected return to FormulaPanel, got: {dbg}"
+        );
     }
 
     /// Regression: CommitFormula must not target virtual categories (_Index, _Dim)
@@ -3727,7 +3764,10 @@ mod tests {
         ctx.buffers = &bufs;
         let effects = CommitCategoryAdd.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("AddCategory"), "Expected AddCategory, got: {dbg}");
+        assert!(
+            dbg.contains("AddCategory"),
+            "Expected AddCategory, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3741,7 +3781,10 @@ mod tests {
         ctx.buffers = &bufs;
         let effects = CommitCategoryAdd.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("CategoryPanel"), "Expected return to CategoryPanel, got: {dbg}");
+        assert!(
+            dbg.contains("CategoryPanel"),
+            "Expected return to CategoryPanel, got: {dbg}"
+        );
     }
 
     // ── Commit item add ────────────────────────────────────────────────
@@ -3802,7 +3845,10 @@ mod tests {
         ctx.buffers = &bufs;
         let effects = CommandModeBackspace.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("Normal"), "Expected return to Normal, got: {dbg}");
+        assert!(
+            dbg.contains("Normal"),
+            "Expected return to Normal, got: {dbg}"
+        );
     }
 
     // ── Execute command ────────────────────────────────────────────────
@@ -3833,7 +3879,10 @@ mod tests {
         let effects = ExecuteCommand.execute(&ctx);
         let dbg = effects_debug(&effects);
         // Should show an error status AND return to Normal
-        assert!(dbg.contains("Normal"), "Expected Normal mode on error, got: {dbg}");
+        assert!(
+            dbg.contains("Normal"),
+            "Expected Normal mode on error, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3842,15 +3891,15 @@ mod tests {
         let layout = make_layout(&m);
         let reg = default_registry();
         let mut bufs = HashMap::new();
-        bufs.insert(
-            "command".to_string(),
-            "add-category Region".to_string(),
-        );
+        bufs.insert("command".to_string(), "add-category Region".to_string());
         let mut ctx = make_ctx(&m, &layout, &reg);
         ctx.buffers = &bufs;
         let effects = ExecuteCommand.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("AddCategory"), "Expected AddCategory effect, got: {dbg}");
+        assert!(
+            dbg.contains("AddCategory"),
+            "Expected AddCategory effect, got: {dbg}"
+        );
     }
 
     // ── Save command ───────────────────────────────────────────────────
@@ -3878,8 +3927,14 @@ mod tests {
         let effects = EnterSearchMode.execute(&ctx);
         assert_eq!(effects.len(), 2);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("SetSearchMode(true)"), "Expected search mode on, got: {dbg}");
-        assert!(dbg.contains("SetSearchQuery"), "Expected query reset, got: {dbg}");
+        assert!(
+            dbg.contains("SetSearchMode(true)"),
+            "Expected search mode on, got: {dbg}"
+        );
+        assert!(
+            dbg.contains("SetSearchQuery"),
+            "Expected query reset, got: {dbg}"
+        );
     }
 
     #[test]
@@ -3891,7 +3946,10 @@ mod tests {
         let effects = ExitSearchMode.execute(&ctx);
         assert_eq!(effects.len(), 1);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("SetSearchMode(false)"), "Expected search mode off, got: {dbg}");
+        assert!(
+            dbg.contains("SetSearchMode(false)"),
+            "Expected search mode off, got: {dbg}"
+        );
     }
 
     // ── Search navigate with query finds match ─────────────────────────
@@ -3922,7 +3980,10 @@ mod tests {
         // Should find the cell with 99 and navigate to it
         if !effects.is_empty() {
             let dbg = effects_debug(&effects);
-            assert!(dbg.contains("SetSelected"), "Expected SetSelected, got: {dbg}");
+            assert!(
+                dbg.contains("SetSelected"),
+                "Expected SetSelected, got: {dbg}"
+            );
         }
         // If empty, the search didn't find it through layout — that's OK since
         // layout coordinates may not map 1:1 with model cells in all cases.
@@ -3939,9 +4000,18 @@ mod tests {
         let effects = CreateAndSwitchView.execute(&ctx);
         let dbg = effects_debug(&effects);
         // Model starts with 1 view ("Default"), so new view should be "View 2"
-        assert!(dbg.contains("CreateView"), "Expected CreateView, got: {dbg}");
-        assert!(dbg.contains("SwitchView"), "Expected SwitchView, got: {dbg}");
-        assert!(dbg.contains("Normal"), "Expected return to Normal, got: {dbg}");
+        assert!(
+            dbg.contains("CreateView"),
+            "Expected CreateView, got: {dbg}"
+        );
+        assert!(
+            dbg.contains("SwitchView"),
+            "Expected SwitchView, got: {dbg}"
+        );
+        assert!(
+            dbg.contains("Normal"),
+            "Expected return to Normal, got: {dbg}"
+        );
     }
 
     // ── Switch view at cursor ──────────────────────────────────────────
@@ -3955,7 +4025,10 @@ mod tests {
         let effects = SwitchViewAtCursor.execute(&ctx);
         // cursor 0, model has "Default" view
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("SwitchView"), "Expected SwitchView, got: {dbg}");
+        assert!(
+            dbg.contains("SwitchView"),
+            "Expected SwitchView, got: {dbg}"
+        );
         assert!(dbg.contains("Normal"), "Expected Normal mode, got: {dbg}");
     }
 
@@ -3980,10 +4053,15 @@ mod tests {
         let ctx = make_ctx(&m, &layout, &reg);
         let effects = DeleteViewAtCursor.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("DeleteView"), "Expected DeleteView, got: {dbg}");
+        assert!(
+            dbg.contains("DeleteView"),
+            "Expected DeleteView, got: {dbg}"
+        );
         // At cursor 0, should NOT have SetPanelCursor (no cursor adjustment needed)
-        assert!(!dbg.contains("SetPanelCursor"),
-            "Expected no cursor adjustment at position 0, got: {dbg}");
+        assert!(
+            !dbg.contains("SetPanelCursor"),
+            "Expected no cursor adjustment at position 0, got: {dbg}"
+        );
     }
 
     // ── Delete formula at cursor ───────────────────────────────────────
@@ -4003,7 +4081,10 @@ mod tests {
         let ctx = make_ctx(&m, &layout, &reg);
         let effects = DeleteFormulaAtCursor.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("RemoveFormula"), "Expected RemoveFormula, got: {dbg}");
+        assert!(
+            dbg.contains("RemoveFormula"),
+            "Expected RemoveFormula, got: {dbg}"
+        );
     }
 
     // ── Commit export ──────────────────────────────────────────────────
@@ -4064,7 +4145,10 @@ mod tests {
         let ctx = make_ctx(&m, &layout, &reg);
         let effects = EnterExportPrompt.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("ExportPrompt"), "Expected ExportPrompt mode, got: {dbg}");
+        assert!(
+            dbg.contains("ExportPrompt"),
+            "Expected ExportPrompt mode, got: {dbg}"
+        );
     }
 
     // ── Toggle prune empty ─────────────────────────────────────────────
@@ -4077,7 +4161,10 @@ mod tests {
         let ctx = make_ctx(&m, &layout, &reg);
         let effects = TogglePruneEmpty.execute(&ctx);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("TogglePruneEmpty"), "Expected TogglePruneEmpty, got: {dbg}");
+        assert!(
+            dbg.contains("TogglePruneEmpty"),
+            "Expected TogglePruneEmpty, got: {dbg}"
+        );
     }
 
     // ── Edit or drill ──────────────────────────────────────────────────
@@ -4131,7 +4218,10 @@ mod tests {
         let effects = cmd.execute(&ctx);
         assert_eq!(effects.len(), 1);
         let dbg = effects_debug(&effects);
-        assert!(dbg.contains("AddCategory"), "Expected AddCategory, got: {dbg}");
+        assert!(
+            dbg.contains("AddCategory"),
+            "Expected AddCategory, got: {dbg}"
+        );
     }
 
     #[test]
diff --git a/src/command/keymap.rs b/src/command/keymap.rs
index fd8ce84..cfbf0e2 100644
--- a/src/command/keymap.rs
+++ b/src/command/keymap.rs
@@ -1017,7 +1017,9 @@ mod tests {
         // hjkl should be bound
         for key in ['h', 'j', 'k', 'l'] {
             assert!(
-                normal.lookup(KeyCode::Char(key), KeyModifiers::NONE).is_some(),
+                normal
+                    .lookup(KeyCode::Char(key), KeyModifiers::NONE)
+                    .is_some(),
                 "Normal mode missing binding for '{}'",
                 key
             );
@@ -1041,9 +1043,7 @@ mod tests {
             .lookup(KeyCode::Char('z'), KeyModifiers::NONE)
             .is_some());
         // Should have Esc to exit
-        assert!(editing
-            .lookup(KeyCode::Esc, KeyModifiers::NONE)
-            .is_some());
+        assert!(editing.lookup(KeyCode::Esc, KeyModifiers::NONE).is_some());
     }
 
     #[test]
@@ -1053,9 +1053,7 @@ mod tests {
         assert!(search
             .lookup(KeyCode::Char('a'), KeyModifiers::NONE)
             .is_some());
-        assert!(search
-            .lookup(KeyCode::Esc, KeyModifiers::NONE)
-            .is_some());
+        assert!(search.lookup(KeyCode::Esc, KeyModifiers::NONE).is_some());
     }
 
     #[test]
diff --git a/src/formula/parser.rs b/src/formula/parser.rs
index 337eb73..3e27fdd 100644
--- a/src/formula/parser.rs
+++ b/src/formula/parser.rs
@@ -592,11 +592,7 @@ mod tests {
     #[test]
     fn parse_where_with_quoted_string_inside_expression() {
         // WHERE inside a formula string with quotes
-        let f = parse_formula(
-            "X = Revenue WHERE Region = \"West Coast\"",
-            "Measure",
-        )
-        .unwrap();
+        let f = parse_formula("X = Revenue WHERE Region = \"West Coast\"", "Measure").unwrap();
         let filter = f.filter.as_ref().unwrap();
         assert_eq!(filter.item, "West Coast");
     }
@@ -714,11 +710,7 @@ mod tests {
     #[test]
     fn split_where_ignores_where_inside_quotes() {
         // WHERE inside quotes should not be treated as a keyword
-        let f = parse_formula(
-            "X = Revenue WHERE Region = \"WHERE\"",
-            "Measure",
-        )
-        .unwrap();
+        let f = parse_formula("X = Revenue WHERE Region = \"WHERE\"", "Measure").unwrap();
         let filter = f.filter.as_ref().unwrap();
         assert_eq!(filter.item, "WHERE");
     }
@@ -773,11 +765,7 @@ mod tests {
 
     #[test]
     fn pipe_quoted_in_where_filter_value() {
-        let f = parse_formula(
-            "X = Revenue WHERE Region = |East Coast|",
-            "Measure",
-        )
-        .unwrap();
+        let f = parse_formula("X = Revenue WHERE Region = |East Coast|", "Measure").unwrap();
         let filter = f.filter.as_ref().unwrap();
         assert_eq!(filter.item, "East Coast");
     }
diff --git a/src/import/csv_parser.rs b/src/import/csv_parser.rs
index ed7e790..05c22f4 100644
--- a/src/import/csv_parser.rs
+++ b/src/import/csv_parser.rs
@@ -218,15 +218,11 @@ mod tests {
 
     #[test]
     fn rfc4180_embedded_comma_in_quoted_field() {
-        let (path, _dir) = create_temp_csv(
-            "Name,Address,Value\n\"Smith, John\",\"123 Main St, Apt 4\",100",
-        );
+        let (path, _dir) =
+            create_temp_csv("Name,Address,Value\n\"Smith, John\",\"123 Main St, Apt 4\",100");
         let records = parse_csv(&path).unwrap();
         assert_eq!(records.len(), 1);
-        assert_eq!(
-            records[0]["Name"],
-            Value::String("Smith, John".to_string())
-        );
+        assert_eq!(records[0]["Name"], Value::String("Smith, John".to_string()));
         assert_eq!(
             records[0]["Address"],
             Value::String("123 Main St, Apt 4".to_string())
@@ -236,9 +232,8 @@ mod tests {
     #[test]
     fn rfc4180_escaped_quotes_in_field() {
         // RFC 4180: doubled quotes ("") inside a quoted field represent a literal quote
-        let (path, _dir) = create_temp_csv(
-            "Name,Description,Value\nWidget,\"A \"\"great\"\" product\",10",
-        );
+        let (path, _dir) =
+            create_temp_csv("Name,Description,Value\nWidget,\"A \"\"great\"\" product\",10");
         let records = parse_csv(&path).unwrap();
         assert_eq!(records.len(), 1);
         assert_eq!(
@@ -250,9 +245,7 @@ mod tests {
     #[test]
     fn rfc4180_newline_in_quoted_field() {
         // RFC 4180: quoted fields may contain newlines
-        let (path, _dir) = create_temp_csv(
-            "Name,Notes,Value\n\"Widget\",\"Line 1\nLine 2\",10",
-        );
+        let (path, _dir) = create_temp_csv("Name,Notes,Value\n\"Widget\",\"Line 1\nLine 2\",10");
         let records = parse_csv(&path).unwrap();
         assert_eq!(records.len(), 1);
         assert_eq!(
@@ -263,9 +256,8 @@ mod tests {
 
     #[test]
     fn rfc4180_embedded_comma_and_quotes_combined() {
-        let (path, _dir) = create_temp_csv(
-            "Name,Desc\n\"Smith, \"\"Jr.\"\"\",\"Said \"\"hello, world\"\"\"",
-        );
+        let (path, _dir) =
+            create_temp_csv("Name,Desc\n\"Smith, \"\"Jr.\"\"\",\"Said \"\"hello, world\"\"\"");
         let records = parse_csv(&path).unwrap();
         assert_eq!(records.len(), 1);
         assert_eq!(
diff --git a/src/import/wizard.rs b/src/import/wizard.rs
index 04e2f62..11666d4 100644
--- a/src/import/wizard.rs
+++ b/src/import/wizard.rs
@@ -859,7 +859,7 @@ mod tests {
         let mut w = ImportWizard::new(raw);
         assert_eq!(w.step, WizardStep::SelectArrayPath);
         w.confirm_path(); // selects first path
-        // Should advance past SelectArrayPath
+                          // Should advance past SelectArrayPath
         assert_ne!(w.step, WizardStep::SelectArrayPath);
         assert!(!w.pipeline.records.is_empty());
     }
@@ -1012,12 +1012,20 @@ mod tests {
             // Toggle Year component (cursor 0 = Year of first time field)
             let had_year_before = {
                 let tc = w.time_category_proposals();
-                !tc.is_empty() && tc[0].date_components.iter().any(|c| *c == DateComponent::Year)
+                !tc.is_empty()
+                    && tc[0]
+                        .date_components
+                        .iter()
+                        .any(|c| *c == DateComponent::Year)
             };
             w.toggle_date_component();
             let has_year_after = {
                 let tc = w.time_category_proposals();
-                !tc.is_empty() && tc[0].date_components.iter().any(|c| *c == DateComponent::Year)
+                !tc.is_empty()
+                    && tc[0]
+                        .date_components
+                        .iter()
+                        .any(|c| *c == DateComponent::Year)
             };
             assert_ne!(had_year_before, has_year_after);
         }
diff --git a/src/model/types.rs b/src/model/types.rs
index c368a63..2c8cf21 100644
--- a/src/model/types.rs
+++ b/src/model/types.rs
@@ -1174,7 +1174,10 @@ mod formula_tests {
             .unwrap();
 
         // Full precision: Tax is exactly 0.75, Total is exactly 10.75
-        assert!(approx_eq(tax, 0.75), "Tax should be 0.75 (full prec), got {tax}");
+        assert!(
+            approx_eq(tax, 0.75),
+            "Tax should be 0.75 (full prec), got {tax}"
+        );
         assert!(
             approx_eq(total, 10.75),
             "Total should be 10.75 (full prec), got {total}"
diff --git a/src/persistence/mod.rs b/src/persistence/mod.rs
index f3cd25e..07d6c27 100644
--- a/src/persistence/mod.rs
+++ b/src/persistence/mod.rs
@@ -848,7 +848,10 @@ mod tests {
     fn autosave_path_inserts_dot_prefix() {
         let p = std::path::Path::new("/home/user/data/budget.improv");
         let auto = super::autosave_path(p);
-        assert_eq!(auto.file_name().unwrap().to_str().unwrap(), ".budget.improv.autosave");
+        assert_eq!(
+            auto.file_name().unwrap().to_str().unwrap(),
+            ".budget.improv.autosave"
+        );
     }
 
     // ── format_md: collapsed groups ─────────────────────────────────────
@@ -856,8 +859,7 @@ mod tests {
     #[test]
     fn format_md_collapsed_group() {
         let mut m = two_cat_model();
-        m.active_view_mut()
-            .toggle_group_collapse("Type", "MyGroup");
+        m.active_view_mut().toggle_group_collapse("Type", "MyGroup");
         let text = format_md(&m);
         assert!(text.contains("collapsed: Type/MyGroup"));
     }
@@ -936,8 +938,7 @@ Type=Food = 42
     #[test]
     fn parse_md_round_trips_collapsed_group() {
         let mut m = two_cat_model();
-        m.active_view_mut()
-            .toggle_group_collapse("Type", "MyGroup");
+        m.active_view_mut().toggle_group_collapse("Type", "MyGroup");
         let text = format_md(&m);
         let loaded = parse_md(&text).unwrap();
         assert!(loaded.active_view().is_group_collapsed("Type", "MyGroup"));
@@ -1006,7 +1007,11 @@ Type=Food = 42
         let lines: Vec<&str> = content.lines().collect();
         assert!(lines.len() >= 2, "Expected header + data, got: {content}");
         // Header should contain column labels
-        assert!(lines[0].contains(','), "Expected CSV header, got: {}", lines[0]);
+        assert!(
+            lines[0].contains(','),
+            "Expected CSV header, got: {}",
+            lines[0]
+        );
     }
 
     #[test]
@@ -1036,11 +1041,9 @@ Type=Food = 42
         m.add_formula(f);
         // Configure view
         m.active_view_mut().set_axis("Month", Axis::Page);
-        m.active_view_mut()
-            .set_page_selection("Month", "Jan");
+        m.active_view_mut().set_page_selection("Month", "Jan");
         m.active_view_mut().hide_item("Type", "Gas");
-        m.active_view_mut()
-            .toggle_group_collapse("Type", "G1");
+        m.active_view_mut().toggle_group_collapse("Type", "G1");
         m.active_view_mut().number_format = ",.0".to_string();
 
         let text = format_md(&m);
diff --git a/src/ui/app.rs b/src/ui/app.rs
index 0da2b36..f1199cc 100644
--- a/src/ui/app.rs
+++ b/src/ui/app.rs
@@ -317,10 +317,12 @@ impl App {
     /// Virtual categories (_Index, _Dim) are always present and don't count.
     pub fn is_empty_model(&self) -> bool {
         use crate::model::category::CategoryKind;
-        self.model
-            .categories
-            .values()
-            .all(|c| matches!(c.kind, CategoryKind::VirtualIndex | CategoryKind::VirtualDim))
+        self.model.categories.values().all(|c| {
+            matches!(
+                c.kind,
+                CategoryKind::VirtualIndex | CategoryKind::VirtualDim
+            )
+        })
     }
 
     pub fn handle_key(&mut self, key: KeyEvent) -> Result<()> {
diff --git a/src/ui/cat_tree.rs b/src/ui/cat_tree.rs
index c768998..ae267e8 100644
--- a/src/ui/cat_tree.rs
+++ b/src/ui/cat_tree.rs
@@ -80,10 +80,7 @@ mod tests {
     fn collapsed_category_shows_header_only() {
         let m = make_model_with_categories(&[("Region", &["North", "South"])]);
         let tree = build_cat_tree(&m, &HashSet::new());
-        let region_entries: Vec<_> = tree
-            .iter()
-            .filter(|e| e.cat_name() == "Region")
-            .collect();
+        let region_entries: Vec<_> = tree.iter().filter(|e| e.cat_name() == "Region").collect();
         assert_eq!(region_entries.len(), 1); // just the header
         assert!(matches!(
             region_entries[0],
@@ -101,13 +98,13 @@ mod tests {
         let mut expanded = HashSet::new();
         expanded.insert("Region".to_string());
         let tree = build_cat_tree(&m, &expanded);
-        let region_entries: Vec<_> = tree
-            .iter()
-            .filter(|e| e.cat_name() == "Region")
-            .collect();
+        let region_entries: Vec<_> = tree.iter().filter(|e| e.cat_name() == "Region").collect();
         // Header + 2 items
         assert_eq!(region_entries.len(), 3);
-        assert!(matches!(region_entries[0], CatTreeEntry::Category { expanded: true, .. }));
+        assert!(matches!(
+            region_entries[0],
+            CatTreeEntry::Category { expanded: true, .. }
+        ));
         assert!(matches!(region_entries[1], CatTreeEntry::Item { .. }));
         assert!(matches!(region_entries[2], CatTreeEntry::Item { .. }));
     }
@@ -124,15 +121,11 @@ mod tests {
 
         let region_items: Vec<_> = tree
             .iter()
-            .filter(|e| {
-                e.cat_name() == "Region" && matches!(e, CatTreeEntry::Item { .. })
-            })
+            .filter(|e| e.cat_name() == "Region" && matches!(e, CatTreeEntry::Item { .. }))
             .collect();
         let product_items: Vec<_> = tree
             .iter()
-            .filter(|e| {
-                e.cat_name() == "Product" && matches!(e, CatTreeEntry::Item { .. })
-            })
+            .filter(|e| e.cat_name() == "Product" && matches!(e, CatTreeEntry::Item { .. }))
             .collect();
         assert_eq!(region_items.len(), 0); // collapsed
         assert_eq!(product_items.len(), 3); // expanded
diff --git a/src/ui/effect.rs b/src/ui/effect.rs
index ac435e4..2e6213c 100644
--- a/src/ui/effect.rs
+++ b/src/ui/effect.rs
@@ -1123,15 +1123,35 @@ mod tests {
     #[test]
     fn transpose_axes_effect() {
         let mut app = test_app();
-        let row_before: Vec<String> = app.model.active_view().categories_on(Axis::Row)
-            .into_iter().map(String::from).collect();
-        let col_before: Vec<String> = app.model.active_view().categories_on(Axis::Column)
-            .into_iter().map(String::from).collect();
+        let row_before: Vec<String> = app
+            .model
+            .active_view()
+            .categories_on(Axis::Row)
+            .into_iter()
+            .map(String::from)
+            .collect();
+        let col_before: Vec<String> = app
+            .model
+            .active_view()
+            .categories_on(Axis::Column)
+            .into_iter()
+            .map(String::from)
+            .collect();
         TransposeAxes.apply(&mut app);
-        let row_after: Vec<String> = app.model.active_view().categories_on(Axis::Row)
-            .into_iter().map(String::from).collect();
-        let col_after: Vec<String> = app.model.active_view().categories_on(Axis::Column)
-            .into_iter().map(String::from).collect();
+        let row_after: Vec<String> = app
+            .model
+            .active_view()
+            .categories_on(Axis::Row)
+            .into_iter()
+            .map(String::from)
+            .collect();
+        let col_after: Vec<String> = app
+            .model
+            .active_view()
+            .categories_on(Axis::Column)
+            .into_iter()
+            .map(String::from)
+            .collect();
         assert_eq!(row_before, col_after);
         assert_eq!(col_before, row_after);
     }
@@ -1313,8 +1333,7 @@ mod tests {
             ("Month".into(), "Jan".into()),
         ]);
         // Set original cell
-        app.model
-            .set_cell(key.clone(), CellValue::Number(42.0));
+        app.model.set_cell(key.clone(), CellValue::Number(42.0));
 
         let records = vec![(key.clone(), CellValue::Number(42.0))];
         StartDrill(records).apply(&mut app);
@@ -1340,8 +1359,7 @@ mod tests {
             ("Type".into(), "Food".into()),
             ("Month".into(), "Jan".into()),
         ]);
-        app.model
-            .set_cell(key.clone(), CellValue::Number(42.0));
+        app.model.set_cell(key.clone(), CellValue::Number(42.0));
 
         let records = vec![(key.clone(), CellValue::Number(42.0))];
         StartDrill(records).apply(&mut app);
@@ -1363,10 +1381,7 @@ mod tests {
             ("Type".into(), "Drink".into()),
             ("Month".into(), "Jan".into()),
         ]);
-        assert_eq!(
-            app.model.get_cell(&new_key),
-            Some(&CellValue::Number(42.0))
-        );
+        assert_eq!(app.model.get_cell(&new_key), Some(&CellValue::Number(42.0)));
         // "Drink" should have been added as an item
         let items: Vec<&str> = app
             .model
@@ -1385,8 +1400,7 @@ mod tests {
             ("Type".into(), "Food".into()),
             ("Month".into(), "Jan".into()),
         ]);
-        app.model
-            .set_cell(key.clone(), CellValue::Number(42.0));
+        app.model.set_cell(key.clone(), CellValue::Number(42.0));
 
         let records = vec![(key.clone(), CellValue::Number(42.0))];
         StartDrill(records).apply(&mut app);
@@ -1465,10 +1479,7 @@ mod tests {
             item: "Food".to_string(),
         }
         .apply(&mut app);
-        assert_eq!(
-            app.model.active_view().page_selection("Type"),
-            Some("Food")
-        );
+        assert_eq!(app.model.active_view().page_selection("Type"), Some("Food"));
     }
 
     // ── Hide/show items ─────────────────────────────────────────────────
@@ -1501,21 +1512,19 @@ mod tests {
             group: "MyGroup".to_string(),
         }
         .apply(&mut app);
-        assert!(
-            app.model
-                .active_view()
-                .is_group_collapsed("Type", "MyGroup")
-        );
+        assert!(app
+            .model
+            .active_view()
+            .is_group_collapsed("Type", "MyGroup"));
         ToggleGroup {
             category: "Type".to_string(),
             group: "MyGroup".to_string(),
         }
         .apply(&mut app);
-        assert!(
-            !app.model
-                .active_view()
-                .is_group_collapsed("Type", "MyGroup")
-        );
+        assert!(!app
+            .model
+            .active_view()
+            .is_group_collapsed("Type", "MyGroup"));
     }
 
     // ── Cycle axis ──────────────────────────────────────────────────────
diff --git a/src/ui/help.rs b/src/ui/help.rs
index aae910d..50d8895 100644
--- a/src/ui/help.rs
+++ b/src/ui/help.rs
@@ -144,22 +144,16 @@ fn page_welcome(s: &HelpStyles) -> Vec<HelpLine> {
         HelpLine::accent("       :add-cat Region          :add-cat Product", s),
         HelpLine::blank(),
         HelpLine::text("  2. Add items to each category:", s),
-        HelpLine::accent(
-            "       :add-items Region North South East West",
-            s,
-        ),
-        HelpLine::accent(
-            "       :add-items Product Widget Gadget",
-            s,
-        ),
+        HelpLine::accent("       :add-items Region North South East West", s),
+        HelpLine::accent("       :add-items Product Widget Gadget", s),
         HelpLine::blank(),
-        HelpLine::text("  3. Navigate with hjkl or arrow keys and press i to edit cells.", s),
+        HelpLine::text(
+            "  3. Navigate with hjkl or arrow keys and press i to edit cells.",
+            s,
+        ),
         HelpLine::blank(),
         HelpLine::text("  4. Add formulas to compute values automatically:", s),
-        HelpLine::accent(
-            "       :formula Product Total = Widget + Gadget",
-            s,
-        ),
+        HelpLine::accent("       :formula Product Total = Widget + Gadget", s),
         HelpLine::blank(),
         HelpLine::text("  5. Save your work:", s),
         HelpLine::accent("       :w mymodel.improv", s),
@@ -187,11 +181,7 @@ fn page_welcome(s: &HelpStyles) -> Vec<HelpLine> {
             s,
         ),
         HelpLine::blank(),
-        HelpLine::dim(
-            "  Tip: press Tab or l/n to go to the next page.",
-            "",
-            s,
-        ),
+        HelpLine::dim("  Tip: press Tab or l/n to go to the next page.", "", s),
     ]
 }
 
@@ -215,10 +205,7 @@ fn page_navigation(s: &HelpStyles) -> Vec<HelpLine> {
         HelpLine::blank(),
         HelpLine::heading("Page-axis cycling", s),
         HelpLine::blank(),
-        HelpLine::text(
-            "  When a category is on the Page axis, only one item is",
-            s,
-        ),
+        HelpLine::text("  When a category is on the Page axis, only one item is", s),
         HelpLine::text(
             "  visible at a time.  Use [ and ] to cycle through them.",
             s,
@@ -229,7 +216,11 @@ fn page_navigation(s: &HelpStyles) -> Vec<HelpLine> {
         HelpLine::blank(),
         HelpLine::heading("Search", s),
         HelpLine::blank(),
-        HelpLine::key("  /", "Start search — type a pattern, matching cells highlight", s),
+        HelpLine::key(
+            "  /",
+            "Start search — type a pattern, matching cells highlight",
+            s,
+        ),
         HelpLine::key("  n", "Jump to next match", s),
         HelpLine::key("  N", "Jump to previous match", s),
         HelpLine::key("  Esc  or  Enter", "Exit search mode", s),
@@ -257,7 +248,11 @@ fn page_editing(s: &HelpStyles) -> Vec<HelpLine> {
         HelpLine::accent("    Text:      hello world", s),
         HelpLine::blank(),
         HelpLine::key("  Enter", "Commit value and move down", s),
-        HelpLine::key("  Tab", "Commit value and move right (stay in edit mode)", s),
+        HelpLine::key(
+            "  Tab",
+            "Commit value and move right (stay in edit mode)",
+            s,
+        ),
         HelpLine::key("  Esc", "Discard edits and return to Normal", s),
         HelpLine::blank(),
         HelpLine::heading("Copy and paste", s),
@@ -280,7 +275,10 @@ fn page_editing(s: &HelpStyles) -> Vec<HelpLine> {
             s,
         ),
         HelpLine::blank(),
-        HelpLine::text("  Example:  in a Product category with items Widget and Gadget:", s),
+        HelpLine::text(
+            "  Example:  in a Product category with items Widget and Gadget:",
+            s,
+        ),
         HelpLine::accent("    :formula Product Total = Widget + Gadget", s),
         HelpLine::blank(),
         HelpLine::text("  Supported operators:  +  -  *  /", s),
@@ -300,10 +298,7 @@ fn page_panels(s: &HelpStyles) -> Vec<HelpLine> {
             "  Panels open on the right side of the screen and give you",
             s,
         ),
-        HelpLine::text(
-            "  quick access to formulas, categories, and views.",
-            s,
-        ),
+        HelpLine::text("  quick access to formulas, categories, and views.", s),
         HelpLine::blank(),
         HelpLine::key("  F", "Toggle Formula panel", s),
         HelpLine::dim("       n", "New formula", s),
@@ -325,14 +320,8 @@ fn page_panels(s: &HelpStyles) -> Vec<HelpLine> {
         HelpLine::blank(),
         HelpLine::heading("Tile select mode (T)", s),
         HelpLine::blank(),
-        HelpLine::text(
-            "  Tiles control which axis each category is placed on.",
-            s,
-        ),
-        HelpLine::text(
-            "  Press T to enter tile-select mode, then:",
-            s,
-        ),
+        HelpLine::text("  Tiles control which axis each category is placed on.", s),
+        HelpLine::text("  Press T to enter tile-select mode, then:", s),
         HelpLine::blank(),
         HelpLine::key("  h / l  (← →)", "Select previous / next category tile", s),
         HelpLine::key("  Space / Enter", "Cycle axis: Row → Col → Page", s),
@@ -345,11 +334,7 @@ fn page_panels(s: &HelpStyles) -> Vec<HelpLine> {
         HelpLine::blank(),
         HelpLine::key("  z", "Toggle collapse of nearest group above cursor", s),
         HelpLine::key("  H", "Hide current row item", s),
-        HelpLine::dim(
-            "       :show-item <cat> <item>",
-            "Restore a hidden item",
-            s,
-        ),
+        HelpLine::dim("       :show-item <cat> <item>", "Restore a hidden item", s),
     ]
 }
 
@@ -362,10 +347,7 @@ fn page_commands(s: &HelpStyles) -> Vec<HelpLine> {
             "  Press : to open the command line.  Commands are entered",
             s,
         ),
-        HelpLine::text(
-            "  vim-style and executed with Enter.  Esc cancels.",
-            s,
-        ),
+        HelpLine::text("  vim-style and executed with Enter.  Esc cancels.", s),
         HelpLine::blank(),
         HelpLine::heading("File operations", s),
         HelpLine::blank(),
@@ -385,7 +367,11 @@ fn page_commands(s: &HelpStyles) -> Vec<HelpLine> {
         HelpLine::blank(),
         HelpLine::key("  :add-cat <name>", "Add a new category", s),
         HelpLine::key("  :add-item <cat> <item>", "Add one item to a category", s),
-        HelpLine::key("  :add-items <cat> a b c ...", "Add multiple items at once", s),
+        HelpLine::key(
+            "  :add-items <cat> a b c ...",
+            "Add multiple items at once",
+            s,
+        ),
         HelpLine::key("  :formula <cat> <Name=expr>", "Add a formula", s),
         HelpLine::blank(),
         HelpLine::heading("Views", s),
diff --git a/src/ui/view_panel.rs b/src/ui/view_panel.rs
index 4defa57..bed47ea 100644
--- a/src/ui/view_panel.rs
+++ b/src/ui/view_panel.rs
@@ -35,10 +35,7 @@ impl<'a> ViewContent<'a> {
         for axis in [Axis::Row, Axis::Column, Axis::Page] {
             let cats = view.categories_on(axis);
             // Filter out virtual categories
-            let cats: Vec<&str> = cats
-                .into_iter()
-                .filter(|c| !c.starts_with('_'))
-                .collect();
+            let cats: Vec<&str> = cats.into_iter().filter(|c| !c.starts_with('_')).collect();
             if !cats.is_empty() {
                 let prefix = match axis {
                     Axis::Row => "R",