feat(dialect): add NameExpr/NameAsExpr and fix schema column qualifiers

[atzedus]

This PR completes the View/Table naming API started in #691 and fixes a codegen bug where generated column prefixes could disagree with the table alias used in SQL.

• BREAKING: View / Table Name() now returns the bare table or view name as a string. SQL builders should use NameExpr() (formerly Name()) and NameAsExpr() (formerly NameAs()).
• Added: Schema() on PostgreSQL and SQLite View types (MySQL is unchanged — no schema/database qualification on models).
• Fixed: Introduced tableColumnAlias in codegen so build*Columns, pkEQ, and pkIN use the same qualifier as View.Alias() when schema is set at construction (schema.table instead of a bare table.Key such as users).
• Updated codegen templates, orm.Preload, factory test templates, CHANGELOG, and view/table docs.

Codegen fix: column qualifiers vs table alias

The bug is not about renaming columns or tables — it is about which prefix codegen attaches to the same users.id when the model is built with a schema.

Assume the same table everywhere:

Field	Value
Table	users
Column	id
Generated model	models.Users

Only the schema at construction differs.

Case A — shared_schema (schema empty at codegen)

Codegen emits:

var Users = psql.NewTablex(..., "", "users", buildUsersColumns("users"), ...)

Runtime:

	Value
Users.Schema()	""
Users.Name()	"users"
Users.Alias()	"users"
Users.Columns.ID	"users"."id"
Users.NameAsExpr()	"users" AS "users"

Manual query:

psql.Select(
    sm.From(models.Users.NameAsExpr()),
    sm.Where(models.Users.Columns.ID.EQ(1)),
)

SELECT "users"."id"
FROM "users" AS "users"
WHERE ("users"."id" = $1)

Prefix users is consistent everywhere. No bug — table.Key ("users") matches Alias().

---

Case B — non-shared schema (schema billing at codegen)

Codegen emits:

var Users = psql.NewTablex(..., "billing", "users", buildUsersColumns(...), ...)

Runtime (dialect):

	Value
Users.Schema()	"billing"
Users.Name()	"users"
Users.Alias()	"billing.users"
Users.NameAsExpr()	"billing"."users" AS "billing.users"
Users.Query() columns (via View.ColumnsExpr)	"billing.users"."id"

Before this PR — codegen passed table.Key ("users") into buildUsersColumns and pkEQ:

	Value
buildUsersColumns("users")	"users"."id"
pkEQ()	Quote("users", "id")

Manual query with the same models.Users and same id:

psql.Select(
    sm.From(models.Users.NameAsExpr()),
    sm.Where(models.Users.Columns.ID.EQ(1)),
)

SELECT "users"."id"
FROM "billing"."users" AS "billing.users"
WHERE ("users"."id" = $1)

Users.Query() alone looked fine (it uses View.ColumnsExpr with parent "billing.users"), but Users.Columns.ID and pkEQ() pointed at "users"."id" while the SQL alias was "billing.users".

After this PR — tableColumnAlias("billing", "users", "users") → "billing.users":

var Users = psql.NewTablex(..., "billing", "users",
    buildUsersColumns("billing.users"), ...)

	Value
Users.Columns.ID	"billing.users"."id"
pkEQ()	Quote("billing.users", "id")

Same manual query:

SELECT "billing.users"."id"
FROM "billing"."users" AS "billing.users"
WHERE ("billing.users"."id" = $1)

Same table users, same column id — only the schema argument changes the prefix, and codegen now matches View.Alias().

Migration

Before (v0.44.0)	After
Users.Name() in sm.From, joins, etc.	Users.NameExpr()
Users.NameAs()	Users.NameAsExpr()
Need qualified name as Expression	NameExpr() / NameAsExpr()
Need unqualified name string	Users.Name()
Schema on psql/sqlite	Users.Schema()

Regenerate models after upgrading bobgen.

[stephenafamo]

This looks good.

I wonder if there is a way to prevent compilation if the models are generated with a version of Bob that is different from the runtime.

[atzedus]

Good question. I think, that exact semver equality at compile time isn’t really doable.

What we can do is a codegen API version: like this does protobuf - https://pkg.go.dev/google.golang.org/protobuf/runtime/protoimpl#EnforceVersion.

This PR already forces a compile break for the Name() → NameExpr() API change.