feat: tray-first UX, text outline, start-at-login toggle, font max 200

- All settings move to flat tray menu; right-click on clock disabled
- ClockLabel: custom QPainterPath text rendering with configurable
  glyph outline (BorderColor) — verified pixel-level offscreen
- Fixed glyph positioning bug (baseline math) caught by isolated test
- Window auto-fits content (adjustSize) — no more oversized clock
- Start at Login: checkable tray item, persisted in QSettings,
  LaunchAgent enable/disable (TDD: roundTrip test caught disable()
  returning false when plist already absent)
- Color dialog: hex/HTML input + 'transparent' + native picker fallback;
  opaque colors stored as #RRGGBB
- Border: glyph outline instead of box border; background still painted
  in paintEvent (QSS doesn't render with WA_TranslucentBackground on macOS)
- Removed window shadow (setHasShadow:NO), no bold, SF Pro Rounded
- Font size dialogs allow up to 200 (was 72)
- macOS: icon template 16pt, light/dark auto-adapt; LaunchAgent points
  to /Applications install

config_manager.h

@@ -33,6 +33,8 @@ public:
     QSize windowSize() const { return m_windowSize; }
     QString primaryTimeZoneId() const { return m_primaryTimeZoneId; }
     QString secondaryTimeZoneId() const { return m_secondaryTimeZoneId; }
+    QColor borderColor() const { return m_borderColor; }
+    int locationFontSize() const { return m_locationFontSize; }
 
     // Setters
     void setFontColor(const QColor &color) { m_fontColor = color; }
@@ -43,6 +45,8 @@ public:
     void setWindowSize(const QSize &size) { m_windowSize = size; }
     void setPrimaryTimeZoneId(const QString &timeZoneId) { m_primaryTimeZoneId = timeZoneId; }
     void setSecondaryTimeZoneId(const QString &timeZoneId) { m_secondaryTimeZoneId = timeZoneId; }
+    void setBorderColor(const QColor &color) { m_borderColor = color; }
+    void setLocationFontSize(int size) { m_locationFontSize = size; }
 
     // Reset to default values
     void resetToDefaults();
@@ -63,6 +67,8 @@ private:
     QSize m_windowSize;
     QString m_primaryTimeZoneId;
     QString m_secondaryTimeZoneId;
+    QColor m_borderColor;
+    int m_locationFontSize;
 };
 
 #endif // CONFIG_MANAGER_H