refactor(db): port preview environments to sqlc

Tranche 3: all 30 raw sites in preview_environments.go — list/detail
joins, access-check reads, create/update/delete, promote, user cleanup,
TTL sweep, and the status-sync UPDATE...FROM CASE. Deployments and
preview_environments schema.sql definitions completed to match runtime.
Shared mapper converts generated rows to the PreviewEnvironment DTO;
DeleteServiceByID from tranche 2 is reused for clone teardown.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/backend/internal/database/sqlcdb/models.go

@@ -136,11 +136,22 @@ type DatabaseService struct {
 }
 
 type Deployment struct {
-	ID        uuid.UUID      `json:"id"`
-	ServiceID uuid.UUID      `json:"service_id"`
-	Status    sql.NullString `json:"status"`
-	CreatedAt sql.NullTime   `json:"created_at"`
-	UpdatedAt sql.NullTime   `json:"updated_at"`
+	ID            uuid.UUID      `json:"id"`
+	ServiceID     uuid.UUID      `json:"service_id"`
+	Version       string         `json:"version"`
+	CommitHash    sql.NullString `json:"commit_hash"`
+	ImageDigest   sql.NullString `json:"image_digest"`
+	Status        sql.NullString `json:"status"`
+	BuildLog      sql.NullString `json:"build_log"`
+	DeploymentLog sql.NullString `json:"deployment_log"`
+	StartedAt     sql.NullTime   `json:"started_at"`
+	CompletedAt   sql.NullTime   `json:"completed_at"`
+	CreatedAt     sql.NullTime   `json:"created_at"`
+	UpdatedAt     sql.NullTime   `json:"updated_at"`
+	ImageName     sql.NullString `json:"image_name"`
+	ImageTag      sql.NullString `json:"image_tag"`
+	RuntimeLog    sql.NullString `json:"runtime_log"`
+	Error         sql.NullString `json:"error"`
 }
 
 type Environment struct {
@@ -274,6 +285,21 @@ type OutboundWebhook struct {
 	UpdatedAt sql.NullTime          `json:"updated_at"`
 }
 
+type PreviewEnvironment struct {
+	ID               uuid.UUID      `json:"id"`
+	ProjectID        uuid.UUID      `json:"project_id"`
+	ServiceID        uuid.UUID      `json:"service_id"`
+	BranchName       string         `json:"branch_name"`
+	PrNumber         sql.NullInt32  `json:"pr_number"`
+	Environment      string         `json:"environment"`
+	Status           string         `json:"status"`
+	Url              sql.NullString `json:"url"`
+	ExpiresAt        time.Time      `json:"expires_at"`
+	CreatedAt        sql.NullTime   `json:"created_at"`
+	UpdatedAt        sql.NullTime   `json:"updated_at"`
+	PreviewServiceID uuid.NullUUID  `json:"preview_service_id"`
+}
+
 type Project struct {
 	ID          uuid.UUID      `json:"id"`
 	Name        string         `json:"name"`