feat(sqltypes): add nullable SQL types with automatic casting

* Introduced SqlNull type for nullable values with auto-casting.
* Implemented JSON, YAML, and XML marshaling/unmarshaling.
* Added specific types for common SQL types (e.g., SqlInt64, SqlString).
* Included utility functions for creating nullable types.
* Added SqlTimeStamp, SqlDate, and SqlTime types with custom formatting.

internal/generatedmodels/sql_public_agent_persona_guardrails.go

@@ -3,13 +3,13 @@ package generatedmodels
 
 import (
 	"fmt"
-	resolvespec_common "github.com/bitechdev/ResolveSpec/pkg/spectypes"
+	sql_types "git.warky.dev/wdevs/relspecgo/pkg/sqltypes"
 	"github.com/uptrace/bun"
 )
 
 type ModelPublicAgentPersonaGuardrails struct {
 	bun.BaseModel  `bun:"table:public.agent_persona_guardrails,alias:agent_persona_guardrails"`
-	ID             resolvespec_common.SqlInt64 `bun:"id,type:bigserial,pk,autoincrement," json:"id"`
+	ID             sql_types.SqlInt64          `bun:"id,type:bigserial,pk,autoincrement," json:"id"`
 	GuardrailID    int64                       `bun:"guardrail_id,type:bigint,notnull," json:"guardrail_id"`
 	PersonaID      int64                       `bun:"persona_id,type:bigint,notnull," json:"persona_id"`
 	RelGuardrailID *ModelPublicAgentGuardrails `bun:"rel:has-one,join:guardrail_id=id" json:"relguardrailid,omitempty"` // Has one ModelPublicAgentGuardrails