feat: add database wrapper interfaces for mssql and postgres

Introduce a DB dialect interface and per-dialect wrappers that expose connection, query and column type operations with pre/post SQL hooks.

internal/app/config/migration.go

@@ -8,9 +8,9 @@ import (
 )
 
 type RetryConfig struct {
-	Attempts int `yaml:"attempts"`
+	Attempts    int `yaml:"attempts"`
 	BaseDelayMs int `yaml:"base_delay_ms"`
-	MaxDelayMs int `yaml:"max_delay_ms"`
+	MaxDelayMs  int `yaml:"max_delay_ms"`
 	MaxJitterMs int `yaml:"max_jitter_ms"`
 }
 
@@ -22,6 +22,8 @@ type JobConfig struct {
 	BatchesPerPartition int         `yaml:"batches_per_partition"`
 	TruncateTarget      bool        `yaml:"truncate_target"`
 	TruncateMethod      string      `yaml:"truncate_method"`
+	MaxPartitionErrrors int         `yaml:"max_partition_errrors"`
+	MaxChunkErrors      int         `yaml:"max_chunk_errors"`
 	Retry               RetryConfig `yaml:"retry"`
 	RowsPerPartition    int64
 }