[Icons] Add an emphasis axis for icon ink

Tint says which hue, style says how much shape, and nothing said how loud.
Call sites that have a hierarchy (a card hover panel's nav strip, the visual
database filter toolbar) could only pick between "the theme color" and
"another theme color", so "this is the important one" had no way to be
expressed and every glyph in a surface arrived with the same weight.

Add `IconEmphasis` as the third axis: Quiet, Secondary, Primary. It travels
inside `IconTint` instead of becoming a fourth `loadThemedIcon` parameter, so
every existing call site keeps working and its look, and emphasis reads as
part of the same "how should this glyph be inked" decision as the tint.

- Primary lifts a neutral glyph to `QPalette::Highlight`, so the surface's own
  action color names the primary action instead of a second gray token, and
  pushes both neutral and tinted glyphs to a 7:1 floor.
- Quiet blends toward the surface and stops at the 3:1 WCAG non-text floor,
  for glyphs that label a control rather than act (the magnifier in a search
  field, a section marker).
- Secondary is the previous color verbatim.

The default ink borrows enough accent to sit off the palette's pole (5.4:1 on
light, 6.4:1 on dark), so the 7:1 primary floor is measurably above it in both
schemes instead of being lost against a near-black or near-white default. The
tests pin that order where it exists, and the hue shift still separates the
levels at a glance.

Disabled glyphs and the Selected -> HighlightedText swap are unchanged at
every emphasis level.

cockatrice/src/interface/theme_icon.h

@@ -46,19 +46,47 @@ enum class IconStyle
     Sticker, ///< filled glyph + dark outline, no disc
 };
 
+/**
+ * @brief Selects how much attention a glyph claims inside its surface.
+ *
+ * Tint says which hue, style says how much shape, emphasis says how loud. The
+ * three are independent: a primary action can be a line glyph in the theme
+ * accent, and a quiet one can be a sticker in a dimmed tone.
+ *
+ * Secondary is the default and the color every icon had before the axis
+ * existed, so existing call sites keep their look. Primary is for the one
+ * action a surface exists for: a neutral primary glyph takes the accent, and a
+ * tinted one is pushed to full contrast. Quiet is for glyphs that label rather
+ * than act, such as the magnifier inside a search field: legible, but never
+ * competing with the buttons next to it.
+ */
+enum class IconEmphasis
+{
+    Quiet,     // labels rather than acts
+    Secondary, // the default action weight
+    Primary,   // the action the surface exists for
+};
+
 /**
  * @brief Selects the color that replaces the `currentColor` sentinel.
  *
  * A palette role follows Qt's structural palette. An application color carries
  * meaning that QPalette cannot express, such as positive and negative states.
- * Callers choose the role. The active theme supplies the value.
+ * Callers pick the role by intent; the theme owns the concrete value. Emphasis
+ * is part of the same decision: both answer how the glyph is inked.
  */
 class IconTint
 {
 public:
     IconTint() = default;
-    IconTint(QPalette::ColorRole role); // implicit: existing palette-role callers
-    IconTint(AppColor::Role role);      // implicit: semantic callers
+    IconTint(QPalette::ColorRole role, IconEmphasis emphasis = IconEmphasis::Secondary); // implicit for role callers
+    IconTint(AppColor::Role role, IconEmphasis emphasis = IconEmphasis::Secondary); // implicit for semantic callers
+
+    /** @brief A neutral glyph in the accent tone, for the surface's primary action. */
+    static IconTint primary();
+
+    /** @brief A dimmed neutral glyph, for a control that labels rather than acts. */
+    static IconTint quiet();
 
     /**
      * @brief Resolves the concrete color for an icon mode.
@@ -74,9 +102,18 @@ public:
      * and holds the glyph to a contrast floor, because a 2px glyph in body-text
      * ink reads thinner than the text beside it. Semantic roles keep the hue the
      * call site asked for.
+     *
+     * Emphasis is applied after the hue: Primary lifts a neutral glyph to the
+     * accent and pushes a tinted one to full contrast; Quiet blends either
+     * toward the surface down to the non-text legibility floor.
      */
     QColor resolve(QIcon::Mode mode) const;
 
+    IconEmphasis getEmphasis() const
+    {
+        return emphasis;
+    }
+
 private:
     enum class Source
     {
@@ -87,6 +124,7 @@ private:
     Source source = Source::Palette;
     QPalette::ColorRole paletteRole = QPalette::WindowText;
     AppColor::Role appRole = AppColor::AccentStrong;
+    IconEmphasis emphasis = IconEmphasis::Secondary;
 };
 
 /**