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/EventStore.mc

@@ -0,0 +1,73 @@
+import Toybox.Application;
+import Toybox.Lang;
+import Toybox.Time;
+
+// Persists events in Application.Storage as an array of dictionaries,
+// ordered oldest → newest. Prunes entries older than Config.RETENTION_SEC
+// whenever loaded.
+module EventStore {
+
+    const KEY = "events";
+
+    function getAll() as Array<Event> {
+        var raw = Application.Storage.getValue(KEY);
+        if (raw == null || !(raw instanceof Array)) {
+            return [];
+        }
+        var out = [];
+        for (var i = 0; i < raw.size(); i++) {
+            out.add(Event.fromDict(raw[i] as Dictionary));
+        }
+        return out;
+    }
+
+    function add(event as Event) as Void {
+        var raw = Application.Storage.getValue(KEY);
+        var arr = (raw instanceof Array) ? raw : [];
+        arr.add(event.toDict());
+        Application.Storage.setValue(KEY, arr);
+    }
+
+    function deleteLast() as Boolean {
+        var raw = Application.Storage.getValue(KEY);
+        if (!(raw instanceof Array) || raw.size() == 0) {
+            return false;
+        }
+        raw = raw.slice(0, raw.size() - 1);
+        Application.Storage.setValue(KEY, raw);
+        return true;
+    }
+
+    function count() as Number {
+        var raw = Application.Storage.getValue(KEY);
+        return (raw instanceof Array) ? raw.size() : 0;
+    }
+
+    function latest() as Event or Null {
+        var raw = Application.Storage.getValue(KEY);
+        if (!(raw instanceof Array) || raw.size() == 0) {
+            return null;
+        }
+        return Event.fromDict(raw[raw.size() - 1] as Dictionary);
+    }
+
+    // Drops events with timestamp < (now - retention).
+    function pruneOld() as Void {
+        var raw = Application.Storage.getValue(KEY);
+        if (!(raw instanceof Array) || raw.size() == 0) {
+            return;
+        }
+        var cutoff = Time.now().value() - Config.RETENTION_SEC;
+        var kept = [];
+        for (var i = 0; i < raw.size(); i++) {
+            var d = raw[i] as Dictionary;
+            var ts = d["ts"];
+            if (ts != null && (ts as Number) >= cutoff) {
+                kept.add(d);
+            }
+        }
+        if (kept.size() != raw.size()) {
+            Application.Storage.setValue(KEY, kept);
+        }
+    }
+}