Phase 1: foundation modules

Central Config with all tunables (retention, GPS timeout, colors,
event type keys, menu item metadata). Event / EventStore handle
persistence via Application.Storage with 7-day pruning. Logger
mirrors the same retention. LayoutMetrics and Haversine provide
resolution-independent geometry helpers. German UI strings and
placeholder menu icons landed alongside so the build stays green.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

source/LayoutMetrics.mc

@@ -0,0 +1,52 @@
+import Toybox.Graphics;
+import Toybox.Lang;
+
+// Resolution-independent layout helpers. All sizes are computed as
+// fractions of the drawable context so the app adapts to any round
+// Garmin display.
+module LayoutMetrics {
+
+    // --- Menu ring geometry --------------------------------------------
+    function centerX(dc as Dc) as Number { return dc.getWidth() / 2; }
+    function centerY(dc as Dc) as Number { return dc.getHeight() / 2; }
+
+    // Radius on which the 10 icons sit.
+    function ringRadius(dc as Dc) as Number {
+        var min = (dc.getWidth() < dc.getHeight()) ? dc.getWidth() : dc.getHeight();
+        return (min * 0.38).toNumber();
+    }
+
+    function iconSize(dc as Dc) as Number {
+        var min = (dc.getWidth() < dc.getHeight()) ? dc.getWidth() : dc.getHeight();
+        return (min * 0.14).toNumber();
+    }
+
+    function selectedIconSize(dc as Dc) as Number {
+        return (iconSize(dc) * 1.3).toNumber();
+    }
+
+    // --- History view sections -----------------------------------------
+    function topSectionHeight(dc as Dc) as Number {
+        return (dc.getHeight() * 0.15).toNumber();
+    }
+
+    function midSectionHeight(dc as Dc) as Number {
+        return (dc.getHeight() * 0.70).toNumber();
+    }
+
+    function bottomSectionY(dc as Dc) as Number {
+        return (dc.getHeight() * 0.85).toNumber();
+    }
+
+    // --- Loading / delete arc radius ------------------------------------
+    function edgeArcRadius(dc as Dc) as Number {
+        var min = (dc.getWidth() < dc.getHeight()) ? dc.getWidth() : dc.getHeight();
+        return (min * 0.48).toNumber();
+    }
+
+    function edgeArcPenWidth(dc as Dc) as Number {
+        var min = (dc.getWidth() < dc.getHeight()) ? dc.getWidth() : dc.getHeight();
+        var w = (min * 0.025).toNumber();
+        return (w < 3) ? 3 : w;
+    }
+}