Deploy: MariaDB from Gitea registry to fix amd64 manifest error

- Use image 10.0.10.205:3000/bert.hausmans/mariadb:11 in compose
- Add deploy/mariadb/Dockerfile (FROM mariadb:11, platform amd64)
- Add scripts/push-mariadb-to-registry.sh to build and push amd64 image once
- Update README with one-time push step and troubleshooting

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/push-mariadb-to-registry.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+# One-time: build MariaDB for linux/amd64 and push to Gitea registry.
+# Use this when the Dockge server gets "no matching manifest for linux/amd64".
+# Run from project root after: docker login 10.0.10.205:3000
+# Usage: ./scripts/push-mariadb-to-registry.sh
+
+set -e
+REGISTRY="${REGISTRY:-10.0.10.205:3000}"
+OWNER="${OWNER:-bert.hausmans}"
+TAG="11"
+
+cd "$(dirname "$0")/.."
+echo "Building MariaDB for linux/amd64..."
+docker build --platform linux/amd64 --tag "$REGISTRY/$OWNER/mariadb:$TAG" --file deploy/mariadb/Dockerfile deploy/mariadb
+echo "Pushing to $REGISTRY/$OWNER/mariadb:$TAG"
+docker push "$REGISTRY/$OWNER/mariadb:$TAG"
+echo "Done. Stack can use: $REGISTRY/$OWNER/mariadb:$TAG"