Explicit module facades

A manifest's exports = ["public.spr"] selects module paths that external packages may import. A declaration export selects names exposed by a module:

import "./internal.spr" as internal

export internal.Widget
export internal.create

Imports come first, then exports, then local declarations and statements. export is contextual in this declaration form; existing identifiers named export remain legal in variables, parameters, fields and other expressions. Exported names retain their simple name. Classes, enums, variants, functions and already-importable top-level values are supported. The underlying declaration and symbol retain their identity: a facade does not copy a mutable value, create another class, wrap a function or change initialization order.

Duplicate visible names, local/alias collisions, missing members and Java member targets are errors. Cyclic imports/reexports are rejected by the existing module graph loader. Chains follow the original declaration in dependency order; API discovery never executes module code.

An exported public facade can expose selected declarations from its own internal modules. Consumers still cannot import those internal paths directly. Neither facades nor API queries bypass the manifest boundary.

sprig api public.spr --json includes reexported declarations and values with reexported: true and originModule relative to the facade. --member uses the same names and signatures as local declarations.

There are no wildcard exports, export-import statements, export renaming, implicit reexports or new visibility modifiers:

export *                              # unsupported
export import "./internal.spr"         # unsupported
export internal.Widget as PublicWidget # unsupported