chore(schema): migrate to GORM V2 with multi-database support

- [x] Implement GORM V2 metadata store with SQLite, PostgreSQL, and MySQL support
- [x] Add database migration system using gormigrate for schema versioning
- [x] Create migration CLI tool with support for migrate, rollback, and status commands
- [x] Add Docker support for migration container (Dockerfile.migrate)
- [x] Implement automatic partition management for PostgreSQL time-series tables
- [x] Add background aggregation worker for download statistics
- [x] Support connection pooling configuration (max_open_conns, max_idle_conns, conn_max_lifetime)
- [x] Add blocking mechanism based on vulnerability thresholds in stats and handlers
- [x] Update Helm charts with migration init containers and multi-database configuration
- [x] Replace deprecated SQLite store with optimized GORM implementation
- [x] Add comprehensive integration tests for MySQL and PostgreSQL
- [x] Update frontend to display blocked packages and storage utilization
- [x] Add goreleaser configuration for migrate binary and container image
- [x] Update configuration examples with database backend options and recommendations

helm/gohoarder/templates/secret.yaml

@@ -53,6 +53,19 @@ data:
   password: {{ .Values.metadata.postgresql.password | b64enc | quote }}
 {{- end }}
 ---
+{{- if and (or (eq .Values.metadata.backend "mysql") (eq .Values.metadata.backend "mariadb")) (not .Values.metadata.mysql.existingSecret) .Values.metadata.mysql.username }}
+apiVersion: v1
+kind: Secret
+metadata:
+  name: {{ include "gohoarder.fullname" . }}-mysql
+  labels:
+    {{- include "gohoarder.labels" . | nindent 4 }}
+type: Opaque
+data:
+  username: {{ .Values.metadata.mysql.username | b64enc | quote }}
+  password: {{ .Values.metadata.mysql.password | b64enc | quote }}
+{{- end }}
+---
 {{- if and .Values.security.scanners.ghsa.enabled (not .Values.security.scanners.ghsa.existingSecret) .Values.security.scanners.ghsa.token }}
 apiVersion: v1
 kind: Secret