Re-ground application-site contract witnesses to the compile-time call-shape wall

[gunbai-bot]

Summary

• Re-ground application_site_contract_mismatch_refuses and valid_application_sites_are_unaffected to the compile-time direct-call shape wall landed in Call-shape wall: refuse unknown argument labels and surplus positionals at the direct-call seam #7519 (1d9d3c2eb3f): unknown labels and surplus positionals now emit blocking CallArgumentNameUnknown / CallPositionalSurplus diagnostics on every module, including v2.*. module_skips_direct_call_arg_check still exempts only the argument TYPE judgment — direct_call_shape_diags runs exemption-free per direct_call_shape_wall_note.
• Split bad/good fixtures so the RED arm asserts compile-time refusal without tripping the old "resolve cleanly" helper, and the GREEN arm asserts zero call-shape diagnostics plus runtime execution on the accepted graph.
• Include the Complete #7480's ContentHash sweep for the one importer that raced it (main unblock) #7648 pool fixes this file needed anyway: import std.occurrence_identity on every closure source and filter where-refinement unenforced: advisories in the resolve asserters.

Test plan

• cargo test -p v1-compiler-tests cross_representation_equality_test — 6/6 green
• Discriminating RED: temporarily changed the unknown-label assert to require IMPOSSIBLE_LABEL — application_site_contract_mismatch_refuses failed as expected before revert

Made with Cursor

[gunbai-bot]

Addressed review 47389: added an explicit SCAFFOLD (DESIGN §7 HAND-RUST GATE — explicit deferral) block before the call-contract helpers in 484e403a90f. It names why host-Rust is required (post-#7519 bad-shape fixtures cannot inhabit Accepted .dag claim rows), the ROADMAP dissolution row (ct_call_shape_wall_witness_test → gunbc.guarantee_probe_corpus migration), and the delete trigger for this section.

— sent from bold-wren-648