Hygiene backlog: duplicated logic single-owners, runner path divergence, quadratic scheduling, workspace

[lann]

From the adversarial review (2026-08-04). Backlog of verified duplication/hygiene items; none urgent, each a drift vector. Checkboxes for piecemeal cleanup:

Single-owner refactors

• Decline-pair lint implemented 3x: sdk-macro (string-level strip_prefix('!'), bypassing core::tags despite already depending on core), Lockfile::validate, and the runner's materialized-cases variant. Static vs materialized justifies two call sites, not three implementations — extract core::tags::decline_pair_check(...).
• "Name is under generated prefix" predicate implemented 5x with one subtly different rule (sdk/lib.rs generated_named allows equality): CaseName::is_under(&str) / covering_prefix() in core; give Inventory a prefix_of mirroring Lockfile::prefix_of (the runner re-implements longest-prefix inline because it's missing).
• core::name::TAGS_SECTION has zero consumers while the string is hardcoded in formats/inventory.rs, sdk-macro (#[link_section] emission), and sdk (case!). Formats should import it; the proc-macro can interpolate it as a literal; document the one genuinely stuck copy (macro_rules! case!).
• Two normalization stories: core::normalize_segment (pub, re-exported, encodes a README rule, zero callers) vs the macro's private ident_to_segment (_->-, the mapping actually applied). Route the macro through core or demote/document normalize_segment for the future JS SDK.

Runner

• Parallel vs sequential paths are copy-pastes that diverged: on new_session failure the parallel path records a per-case trap and continues; the sequential path aborts the run, leaving JSONL unterminated. Extract a shared helper; per-case-trap + continue is the policy consistent with "poisoning is contained".
• Quadratic scheduling pre-pass: tags_of is a linear scan + per-hit Tags::new(clone) called once per name across three passes (drift check, decline-pair, plan) — O(names x cases) at exactly the ~8k scale M1 targets. Same pattern in aggregate (loop-invariant case_tags rebuilt per target). One upfront map each.
• COMPONENT_TEST_PROFILE env knob is documented nowhere and double-enumerates per session.

Aggregate/CLI

• Undeclared target cascades: after pushing "not declared in the manifest", the loop proceeds with missing = &[], producing a false applicability error per decline-tagged case. continue after the root-cause error.
• Failure predicate Fail | NotReached duplicated between Aggregate::has_failures and the CLI counting loop.

JS runner

• runner.mjs: on a non-verdict throw the concurrent drain promise is abandoned and ctx/observer never disposed; if the trap errors the stream, the unhandled rejection kills Node and masks the real trap. try/finally + await drain.catch(() => {}). Verdict-mapping switch duplicated across both .mjs runners.

Provider (moved from #42)

• Silent diagnostic drop window: a diagnostic call that finds the writer taken by a concurrent call black-holes its message while the runner reports diagnostics-complete: true (components/provider/src/lib.rs, take/put-back protocol). Unreachable through in-repo runners today (a parked reader makes write_one complete synchronously — verified 50/50 delivery under 50-way join), but the failure mode is silent loss marked complete; a real fix needs a pending-message queue drained on put-back. The sibling drop/close inversion was fixed in 38faf9a.

Workspace

• default-members = ["crates/*"] would collapse the 4-crate exclusion list maintained in three places (justfile lint/test + AGENTS.md); the "native tests fail" rationale is already gone from AGENTS.md (7902841).
• components/*/Cargo.toml hardcode version/edition (done in 450d94d)
• component-test-runner lacks description; wasmparser = "0.243" in formats is stale vs the 0.25x already in-tree via wasmtime (duplicate build).

From #34 (parked at crate split time)

• Move Provenance out of component-test-core into component-test-results (currently defined in core, re-exported by results). Deferred deliberately: it is the one Results schema: extract a guest-consumable crate; runner-cli hand-rolls the wire format #34 piece with breakage potential for external consumers; do it at a real semver moment.