ci: add golangci-lint config and fix formatting

- Add .golangci.yml with minimal linters (govet, ineffassign)
- Run gofmt -s and goimports on all files to fix formatting
- Disable fieldalignment and copylocks checks in govet

internal/backup/incremental.go

@@ -17,19 +17,19 @@ const (
 type IncrementalMetadata struct {
 	// BaseBackupID is the SHA-256 checksum of the base backup this incremental depends on
 	BaseBackupID string `json:"base_backup_id"`
-	
+
 	// BaseBackupPath is the filename of the base backup (e.g., "mydb_20250126_120000.tar.gz")
 	BaseBackupPath string `json:"base_backup_path"`
-	
+
 	// BaseBackupTimestamp is when the base backup was created
 	BaseBackupTimestamp time.Time `json:"base_backup_timestamp"`
-	
+
 	// IncrementalFiles is the number of changed files included in this backup
 	IncrementalFiles int `json:"incremental_files"`
-	
+
 	// TotalSize is the total size of changed files (bytes)
 	TotalSize int64 `json:"total_size"`
-	
+
 	// BackupChain is the list of all backups needed for restore (base + incrementals)
 	// Ordered from oldest to newest: [base, incr1, incr2, ...]
 	BackupChain []string `json:"backup_chain"`
@@ -39,16 +39,16 @@ type IncrementalMetadata struct {
 type ChangedFile struct {
 	// RelativePath is the path relative to PostgreSQL data directory
 	RelativePath string
-	
+
 	// AbsolutePath is the full filesystem path
 	AbsolutePath string
-	
+
 	// Size is the file size in bytes
 	Size int64
-	
+
 	// ModTime is the last modification time
 	ModTime time.Time
-	
+
 	// Checksum is the SHA-256 hash of the file content (optional)
 	Checksum string
 }
@@ -57,13 +57,13 @@ type ChangedFile struct {
 type IncrementalBackupConfig struct {
 	// BaseBackupPath is the path to the base backup archive
 	BaseBackupPath string
-	
+
 	// DataDirectory is the PostgreSQL data directory to scan
 	DataDirectory string
-	
+
 	// IncludeWAL determines if WAL files should be included
 	IncludeWAL bool
-	
+
 	// CompressionLevel for the incremental archive (0-9)
 	CompressionLevel int
 }
@@ -72,11 +72,11 @@ type IncrementalBackupConfig struct {
 type BackupChainResolver interface {
 	// FindBaseBackup locates the base backup for an incremental backup
 	FindBaseBackup(ctx context.Context, incrementalBackupID string) (*BackupInfo, error)
-	
+
 	// ResolveChain returns the complete chain of backups needed for restore
 	// Returned in order: [base, incr1, incr2, ..., target]
 	ResolveChain(ctx context.Context, targetBackupID string) ([]*BackupInfo, error)
-	
+
 	// ValidateChain verifies all backups in the chain exist and are valid
 	ValidateChain(ctx context.Context, chain []*BackupInfo) error
 }
@@ -85,10 +85,10 @@ type BackupChainResolver interface {
 type IncrementalBackupEngine interface {
 	// FindChangedFiles identifies files changed since the base backup
 	FindChangedFiles(ctx context.Context, config *IncrementalBackupConfig) ([]ChangedFile, error)
-	
+
 	// CreateIncrementalBackup creates a new incremental backup
 	CreateIncrementalBackup(ctx context.Context, config *IncrementalBackupConfig, changedFiles []ChangedFile) error
-	
+
 	// RestoreIncremental restores an incremental backup on top of a base backup
 	RestoreIncremental(ctx context.Context, baseBackupPath, incrementalPath, targetDir string) error
 }
@@ -101,8 +101,8 @@ type BackupInfo struct {
 	Timestamp time.Time `json:"timestamp"`
 	Size      int64     `json:"size"`
 	Checksum  string    `json:"checksum"`
-	
+
 	// New fields for incremental support
-	BackupType BackupType           `json:"backup_type"`           // "full" or "incremental"
+	BackupType  BackupType           `json:"backup_type"`           // "full" or "incremental"
 	Incremental *IncrementalMetadata `json:"incremental,omitempty"` // Only present for incremental backups
 }