Route contributions beyond the admin tabs (which auto-generate from
admin_tabs/0 / user_dashboard_tabs/0): the PUBLIC portal surface.
generate/1 is core's compile_module_public_routes hook — the AST
splices into the host router at top level, before the /:locale public
surface, so the path uses a LITERAL first segment (/portal/...), the
documented safe shape there. No locale segment in v1 (one less
unvalidated public param — panel #16).