feat(easter-eggs): add easter egg hunt addon across all worlds

50 eggs hidden per child world (Jamie/Lyla/Mya) in 8 creative hiding
scenes (barrels, hay bales, flower patches, logs, fences, crafting
tables, mossy ledges, leaf clusters). Each world uses a distinct glazed
terracotta colour. Found eggs are tracked via player tags which persist
across server transfers; lobby reads tags and maintains a scoreboard
leaderboard (egg_count objective). Gitea deploy workflow updated to
include easter-egg-addon/ and docker-compose.yml in checkout.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

easter-egg-addon/easter_egg_lobby_BP/manifest.json

@@ -0,0 +1,25 @@
+{
+  "format_version": 2,
+  "header": {
+    "name": "Easter Egg Lobby",
+    "description": "Tracks egg counts from all worlds and shows a leaderboard in the lobby",
+    "uuid": "e3a4c5d6-7890-1234-cdef-012345678902",
+    "version": [1, 0, 0],
+    "min_engine_version": [1, 21, 0]
+  },
+  "modules": [
+    {
+      "type": "script",
+      "language": "javascript",
+      "uuid": "f4b5d6e7-8901-2345-def0-123456789013",
+      "version": [1, 0, 0],
+      "entry": "scripts/main.js"
+    }
+  ],
+  "dependencies": [
+    {
+      "module_name": "@minecraft/server",
+      "version": "1.17.0"
+    }
+  ]
+}