Add deploy.sh script for manual builds + .env.example + .gitignore for .env

.env.example

@@ -0,0 +1,13 @@
+# Dostalgia — Environment Variables
+# Copy this to .env and fill in your values.
+# Source it before running deploy.sh:  source .env && ./deploy.sh
+
+# IGDB (Twitch) credentials — required for game artwork & metadata
+TWITCH_CLIENT_ID=your_client_id_here
+TWITCH_CLIENT_SECRET=your_client_secret_here
+
+# Optional overrides (defaults are fine for most setups)
+# IMAGE_NAME=dostalgia
+# CONTAINER_NAME=dostalgia
+# HOST_PORT=8765
+# DATA_DIR=/opt/data/workspace/dostalgia/data