reference_conservation: the census names a normalize refusal's reason and locus

[gunbai-bot]

XL-2 N7 follow-up to #13305 (observability gap, manager item 3).

Problem. reference_conservation_census_for_paths consumed normalize's refusal diagnostics only as a cover, so a refused module printed refused=N and refusal-not-at-or-above per atom with no reason or locus. That is why v2.compiler.service_realization's post-parse refusal looked causeless.

Change. ReferenceConservationReport carries normalize_refusal (fatal reason + locus, node locus resolved to text through the module's span index). The summary line always prints refusal=<stage>:<reason>@<locus> or refusal=none. RFM row census_counts_a_stage_refusal_without_naming_its_cause.

Controls (fixture module that refuses at normalize, plus an accepting control), all 6 claims PASS on BuildBuddy via claim_batch:

• a_refused_normalization_carries_its_fatal_reason_located_in_text_holds
• a_refused_normalization_prints_its_reason_and_locus_on_the_summary_line_holds
• an_accepted_module_prints_no_refusal_on_the_summary_line_holds
• plus the 3 existing role-gap / clean-control claims.

No rows added to floor_cross_claim_pure_producers_warm.

The cause it would have printed (measured with a probe over main's file): on #13305's head normalize refused with normalize_reason_post_normalize_not_well_formed at bytes 0..6 (the module keyword); on #13309's head and on main it accepts. Nothing to fix in service_realization.dag.

🤖 Generated with Claude Code

[gunbai-bot]

Addressed review 76036: deleted conservation_refusal_locus_resolved / conservation_refusal_locus_text / conservation_refusal_extent_text. ReferenceConservationNormalizeRefusal is now { fatal: Diagnostic, located: String }, where located is v2.std.lens_verdict lens_verdict_diagnostic_located_text_in_spans(d: fatal, index: spans) (tokenize/parse arm uses the same door with span_index_empty()). Summary line ends refusal=normalize:<reason> @ <file> bytes 47..54 (last on the line, since the located text has spaces). All 6 reference_conservation claims PASS on BuildBuddy via claim_batch.