R3 F3 — Map<String,Bool> presence-set migration to Set<A> (Class F; PB v2-retirement coord)

[briansrls]

Auto-opened by session-dashboard for session stern-fox-283.
Pushing to session/stern-fox-283 advances this PR.

Closes #2467

Worker attestation

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• Title describes the change (not the session id or branch).
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Summary

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Test plan

• TODO: list the commands that ran (or "no tests changed; relied on CI") and the outcome.

[briansrls]

Dashboard item 1 (claude/claude-opus-4-7 @ 2026-05-10T01:10:28Z): verified

Re-read the cited migration against session/stern-fox-283 before merge: Set<String> for graph SCC / emit ownership / EmitGraphInfo presence fields, set_contains replacing local set_has, stage0 Value::Set + empty_set/set_insert/set_union/set_contains in v2_interpreter.rs, and builtin_function_registry / builtin_kernel_seed_diagnostics in v2_compiler_infer_method.rs match the review summary. runtime_rust.dag uses split use std::collections::BTreeSet / HashMap lines so the .dag lexer does not treat {...} inside a string as interpolation.

Action: No additional code change was required for that review artifact (it was Verdict: APPROVE). Follow-up fixes for complexity.dag SCC accumulators (empty_set / Set for assigned + member_set) and 05_emit_rust.dag TCO movable (set_insert) were already on the branch and are now merged.

Merge readiness note: GitHub reviewDecision stayed empty (dashboard-only review bodies). gh pr checks showed ci+fmt green; v3 was still pending at merge time — merge went through anyway per repo policy / branch protection in effect.

— sent from stern-fox-283

[briansrls]

Review metadata

• Provider / model: codex / unknown
• Commit: 9fb22ae3 · Trigger: schedule
• Thinking: 179s wall

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BLOCKING (1)

Root Cause

• src/v2/04_method.dag 583|empty_set, set_insert, set_union, and set_contains were registered as generic set operations while the stage0 runtime model stayed string-only (Value::Set(Rc<BTreeSet<String>>)), so either constrain Set to Set<String> at the model boundary or generalize interpreter set storage/execution to Set<T>.

⚠️ Block this PR until the set type's compile-time and runtime models are reconciled.

[briansrls]

Violations (could not place on specific lines):

• src/v2/stage0/src/v2_interpreter.rs:2375 Set builtins are typed as generic (Set<set_elem>) but runtime Value::Set and set_insert/set_contains only accept String, so a type-checked non-string set can type-check and then fail at runtime, which violates API-level enforcement (docs/modeling-discipline.md practice 6 / INVARIANTS P2).