feat(bun): generate native Go array slices for PostgreSQL array columns

Bun's pgdialect scans/appends native slices directly, so array columns
(text[], integer[], uuid[], ...) always generate as plain []string,
[]int32, etc. with an explicit "array" bun tag, regardless of --types
(sqltypes/stdlib/baselib). The SqlXxxArray wrapper types are no longer
used for Bun array columns (gorm is unaffected and keeps using them).

Adds --array-nullable pointer_slice to represent nullable array columns
as *[]T instead of []T, so callers can distinguish SQL NULL (nil) from
'{}' (pointer to an empty slice). Verified end-to-end against a live
PostgreSQL instance for NULL/{}/populated arrays in every --types mode.

Closes #13

vendor/github.com/jackc/puddle/v2/context.go

@@ -0,0 +1,24 @@
+package puddle
+
+import (
+	"context"
+	"time"
+)
+
+// valueCancelCtx combines two contexts into one. One context is used for values and the other is used for cancellation.
+type valueCancelCtx struct {
+	valueCtx  context.Context
+	cancelCtx context.Context
+}
+
+func (ctx *valueCancelCtx) Deadline() (time.Time, bool) { return ctx.cancelCtx.Deadline() }
+func (ctx *valueCancelCtx) Done() <-chan struct{}       { return ctx.cancelCtx.Done() }
+func (ctx *valueCancelCtx) Err() error                  { return ctx.cancelCtx.Err() }
+func (ctx *valueCancelCtx) Value(key any) any           { return ctx.valueCtx.Value(key) }
+
+func newValueCancelCtx(valueCtx, cancelContext context.Context) context.Context {
+	return &valueCancelCtx{
+		valueCtx:  valueCtx,
+		cancelCtx: cancelContext,
+	}
+}