Initial commit: webtrees Email Newsletter module

Recurring email newsletter for webtrees 2.2+. Each enabled tree
sends upcoming birthdays of living individuals, optional marriage
anniversaries of intact couples, and a once-per-calendar-month
historical section of births and deaths of deceased individuals.

Triggered exclusively by an external scheduler (system cron,
systemd timer, etc.) hitting a token-gated HTTP endpoint — never
on visitor page loads. The "is it due?" decision is idempotent
within the configured frequency window.

Per-user subscription is integrated into the built-in
/my-account/{tree} page via a custom view + a decorated
AccountUpdate handler. Admins can add external addresses and
trigger an immediate send for testing. Email body renders in
German for German-language users; English otherwise. Birthdays
and anniversaries are formatted with the upcoming-event ordinal
age (e.g. "45th birthday" / "45. Geburtstag").

composer.json

@@ -0,0 +1,32 @@
+{
+    "name": "alex/webtrees-email-newsletter",
+    "description": "Sends recurring email newsletters with upcoming birthdays, marriage anniversaries, and historical events from the family tree.",
+    "license": "AGPL-3.0-or-later",
+    "type": "webtrees-module",
+    "keywords": [
+        "webtrees",
+        "module",
+        "newsletter",
+        "email",
+        "birthday",
+        "anniversary"
+    ],
+    "authors": [
+        {
+            "name": "Alex",
+            "role": "Developer"
+        }
+    ],
+    "minimum-stability": "dev",
+    "prefer-stable": true,
+    "require": {
+        "php": ">=8.2",
+        "ext-json": "*",
+        "fisharebest/webtrees": "~2.2.0 || dev-main"
+    },
+    "autoload": {
+        "psr-4": {
+            "EmailNewsletter\\": "src/"
+        }
+    }
+}