Address review feedback: dedupe scrub-precision formula, fix stale comment

Extract initialScrubDecimalPlaces so click-drag and scroll-to-scrub compute
the starting decimal precision from one place instead of two independently
duplicated formulas. Also correct EyedropperButton's comment now that
showsTypeLabels is hardcoded true and the fade it describes is vestigial.

Author: superhighfives

Pika/Views/EditableColorValue.swift

@@ -671,13 +671,7 @@ struct ColorComponentField: View {
         if scrollOrigin == nil {
             scrollOrigin = Double(text.trimmingCharacters(in: .whitespaces)) ?? 0
             scrollAccumulated = 0
-            scrollDecimalPlaces = min(
-                ScrubTextField.precisionRange.upperBound,
-                max(
-                    Self.naturalDecimalPlaces(forRange: component.range),
-                    Self.stableDecimalPlaces(for: text)
-                )
-            )
+            scrollDecimalPlaces = Self.initialScrubDecimalPlaces(forRange: component.range, text: text)
             onDragBegin()
         }
         guard let origin = scrollOrigin else { return }
@@ -746,4 +740,17 @@ struct ColorComponentField: View {
         let decimals = text.distance(from: text.index(after: dotIndex), to: text.endIndex)
         return max(2, min(4, decimals))
     }
+
+    /// Decimal places to start a scrub session at: whichever is finer, the precision this
+    /// component's drag step can actually resolve (`naturalDecimalPlaces`) or the precision
+    /// already on display (`stableDecimalPlaces`, so starting a scrub never truncates what's
+    /// shown), capped at `ScrubTextField.precisionRange`'s ceiling. Shared by click-drag
+    /// (`ScrubTextField.beginDrag`) and scroll-to-scrub (`handleScrollDelta`) so the two paths
+    /// can't drift out of sync the way their digit-budget math already has once.
+    static func initialScrubDecimalPlaces(forRange range: ClosedRange<Double>?, text: String) -> Int {
+        min(
+            ScrubTextField.precisionRange.upperBound,
+            max(naturalDecimalPlaces(forRange: range), stableDecimalPlaces(for: text))
+        )
+    }
 }

Pika/Views/EyedropperButton.swift

@@ -127,9 +127,10 @@ struct EyedropperButton: View {
             // clicks. The type label and colour name disable hit-testing so clicks fall
             // through to the pick button behind them.
             VStack(alignment: .leading, spacing: 2.0) {
-                // Visibility is size-aware (`adaptive.showsTypeLabels` already folds in the
-                // preview-pill overlap) so labels fade out as the window shrinks and return
-                // when it grows again. The invalid pill overrides the fade so it's never hidden.
+                // `adaptive.showsTypeLabels` is hardcoded `true` (ContentView.swift) as of
+                // `81fe9f9`, so the fade below is currently vestigial — kept in case that's
+                // revisited, rather than stripped along with the conditional that once drove it.
+                // The invalid pill overrides the fade so it's never hidden.
                 let showsTypeLabel = adaptive.showsTypeLabels
                 HStack(alignment: .firstTextBaseline, spacing: 6.0) {
                     Text(eyedropper.type.description)

Pika/Views/ScrubTextField.swift

@@ -466,15 +466,7 @@ final class ScrubTextField: NSTextField {
     private func beginDrag(at location: NSPoint) {
         dragAnchorValue = Double(stringValue.trimmingCharacters(in: .whitespaces)) ?? 0
         dragAnchorX = location.x
-        // Whichever is finer: the precision this component's drag step can actually resolve, or
-        // the precision already on display (so starting a scrub never truncates what's shown).
-        dragDecimalPlaces = min(
-            Self.precisionRange.upperBound,
-            max(
-                ColorComponentField.naturalDecimalPlaces(forRange: range),
-                ColorComponentField.stableDecimalPlaces(for: stringValue)
-            )
-        )
+        dragDecimalPlaces = ColorComponentField.initialScrubDecimalPlaces(forRange: range, text: stringValue)
         dragBaseDecimalPlaces = dragDecimalPlaces
         NSCursor.resizeLeftRight.set()
         onDragBegin?()