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/pgx/v5/pgxpool/doc.go

@@ -0,0 +1,27 @@
+// Package pgxpool is a concurrency-safe connection pool for pgx.
+/*
+pgxpool implements a nearly identical interface to pgx connections.
+
+Creating a Pool
+
+The primary way of creating a pool is with [pgxpool.New]:
+
+    pool, err := pgxpool.New(context.Background(), os.Getenv("DATABASE_URL"))
+
+The database connection string can be in URL or keyword/value format. PostgreSQL settings, pgx settings, and pool settings can be
+specified here. In addition, a config struct can be created by [ParseConfig].
+
+    config, err := pgxpool.ParseConfig(os.Getenv("DATABASE_URL"))
+    if err != nil {
+        // ...
+    }
+    config.AfterConnect = func(ctx context.Context, conn *pgx.Conn) error {
+        // do something with every new connection
+    }
+
+    pool, err := pgxpool.NewWithConfig(context.Background(), config)
+
+A pool returns without waiting for any connections to be established. Acquire a connection immediately after creating
+the pool to check if a connection can successfully be established.
+*/
+package pgxpool