LR-CROP-STRAIGHTEN: slider values say they can be typed

Every slider's value already takes a typed number when clicked, which
is how to enter an exact crop angle (#534), but nothing said so.
Hovering a slider value now shows "Click to type a value", translated
in all seven locales. A headless test hovers the Straighten value and
finds the hint painted.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/locales/de.json

@@ -1887,5 +1887,6 @@
   "Pending photo action cancelled": "Pending photo action cancelled",
   "Pending photo action cancelled because its library or photo changed": "Pending photo action cancelled because its library or photo changed",
   "ONNX model": "ONNX model",
-  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions"
+  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions",
+  "Click to type a value": "Klicken, um einen Wert einzugeben"
 }

crates/ui-egui/locales/es.json

@@ -1732,5 +1732,6 @@
   "Pending photo action cancelled": "Pending photo action cancelled",
   "Pending photo action cancelled because its library or photo changed": "Pending photo action cancelled because its library or photo changed",
   "ONNX model": "ONNX model",
-  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions"
+  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions",
+  "Click to type a value": "Hacer clic para escribir un valor"
 }

crates/ui-egui/locales/ja.json

@@ -1732,5 +1732,6 @@
   "Pending photo action cancelled": "Pending photo action cancelled",
   "Pending photo action cancelled because its library or photo changed": "Pending photo action cancelled because its library or photo changed",
   "ONNX model": "ONNX model",
-  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions"
+  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions",
+  "Click to type a value": "クリックして値を入力"
 }

crates/ui-egui/locales/pt-br.json

@@ -1732,5 +1732,6 @@
   "Pending photo action cancelled": "Pending photo action cancelled",
   "Pending photo action cancelled because its library or photo changed": "Pending photo action cancelled because its library or photo changed",
   "ONNX model": "ONNX model",
-  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions"
+  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions",
+  "Click to type a value": "Clique para digitar um valor"
 }

crates/ui-egui/locales/ru.json

@@ -1405,5 +1405,6 @@
   "Pending photo action cancelled": "Pending photo action cancelled",
   "Pending photo action cancelled because its library or photo changed": "Pending photo action cancelled because its library or photo changed",
   "ONNX model": "ONNX model",
-  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions"
+  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions",
+  "Click to type a value": "Щёлкните, чтобы ввести значение"
 }

crates/ui-egui/locales/zh-hans.json

@@ -1732,5 +1732,6 @@
   "Pending photo action cancelled": "Pending photo action cancelled",
   "Pending photo action cancelled because its library or photo changed": "Pending photo action cancelled because its library or photo changed",
   "ONNX model": "ONNX model",
-  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions"
+  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions",
+  "Click to type a value": "点击以输入数值"
 }

crates/ui-egui/locales/zh-hant.json

@@ -1732,5 +1732,6 @@
   "Pending photo action cancelled": "Pending photo action cancelled",
   "Pending photo action cancelled because its library or photo changed": "Pending photo action cancelled because its library or photo changed",
   "ONNX model": "ONNX model",
-  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions"
+  "commercial use subject to GPL conditions": "commercial use subject to GPL conditions",
+  "Click to type a value": "按一下以輸入數值"
 }

crates/ui-egui/src/tests_crop_rotate.rs

@@ -99,3 +99,18 @@ fn the_angle_reads_like_the_straighten_value() {
     assert_eq!(crop_angle_label(-12.254), "-12.25°");
     assert_eq!(crop_angle_label(-0.001), "0.00°", "no minus zero, and every zero the same");
 }
+
+/// Hovering the Straighten value says that a value can be typed there.
+#[test]
+fn the_straighten_value_says_it_can_be_typed() {
+    let mut h = crop_tool();
+    let r = h.request("ui.hoverWidget", json!({"id": "sliderValue:crop.angle"}), T);
+    assert_eq!(r["ok"], true, "{r}");
+    // tooltips wait for the pointer to rest
+    let _ = h.step_until(Duration::from_secs(5), |h| h.painted_text().iter().any(|t| t.contains("type")));
+    assert!(
+        h.painted_text().iter().any(|t| t == "Click to type a value"),
+        "{:?}",
+        h.painted_text().iter().filter(|t| t.contains("lick")).collect::<Vec<_>>()
+    );
+}

crates/ui-egui/src/widgets.rs

@@ -180,6 +180,8 @@ pub fn slider(ui: &mut Ui, spec: &ControlSpec, value: f64, enabled: bool, label_
     let value_rect = Rect::from_min_max(pos2(label_rect.right() - 64.0, label_rect.top()), label_rect.max);
     let value_resp = ui.interact(value_rect, id.with("value"), if enabled { Sense::click() } else { Sense::hover() });
     register(ui.ctx(), format!("sliderValue:{}", spec.id), value_rect);
+    // say that an exact value can be typed here (issue #534: an exact crop angle was hard to find)
+    let value_resp = if enabled { value_resp.on_hover_text(crate::i18n::tr("Click to type a value")) } else { value_resp };
     let typing_id = id.with("typing");
     let field_id = id.with("typingField");
     // the text being typed and how many frames the field has been up: it takes the keyboard on its