[flavor365]

Closes #1194, Closes #1197, Closes #1198, Closes #1199

Summary

Four issues across packages/config and scripts/ that harden the shared-config checker and fixture validator with missing parity checks, documented contracts, and tests for the deny-by-default safety property.

Changes by issue

#1194 — Barrel export parity check

check-shared-config.mjs now verifies that every value symbol re-exported by packages/config/src/index.ts is actually exported by packages/config/src/networks.ts, and vice-versa. A rename or dropped export in networks.ts now fails config:check immediately with SHARED_CONFIG_BARREL_EXPORT_MISMATCH instead of surfacing only as a downstream TypeScript error.

• Added checkBarrelExports() — parses barrel re-exports (export { ... } from './networks') and networks.ts declarations (export function/const/class NAME), reports missing and extra symbols.
• Type-only exports (export type { ... }) are excluded since they vanish at runtime.
• Wired into checkSharedConfig() alongside existing checkPackageFiles.
• Tests: passing case, missing-export case, extra-export case.

#1197 — parseRustTickVectors null contract

scripts/fixtures.d.ts declares parseRustTickVectors can return null, but no test covered that branch.

• Tests now assert: null for sources with no mod fixture_tests block; [] when the module exists but has no vector tuples (distinguishing null/not-found from []/found-but-empty); successful parse returns entries shaped { tick: number, sqrtPriceX96: string }.

#1198 — EXEMPT_WORKSPACES deny-by-default tests

The deny-by-default guarantee is the core safety property of the checker but was not covered by any test. A regression inverting the exemption logic would have passed the existing suite.

• Added optional exempt parameter to checkSharedConfig (threaded through checkTsconfigs, checkEslintStatic, checkEslintEffective, lintWorkspaces) so exemption behavior is testable without mutating the frozen EXEMPT_WORKSPACES object.
• Tests assert: TSCONFIG_MISSING for a workspace without tsconfig.json; ESLINT_MISSING for a workspace with a lint script but no eslint config; exempting one workspace suppresses only its errors while non-exempt workspace errors remain.

#1199 — checkFixtures/writeFixtures error semantics

The declared return types didn't specify what fixtures and written mean when errors is non-empty. Callers had to guess whether a non-empty errors meant nothing was written or a partial write occurred.

• Updated JSDoc in fixtures.d.ts: checkFixtures always reports the number of inspected fixtures regardless of errors; writeFixtures is all-or-nothing (written is [] when errors is non-empty).
• Tests assert: checkFixtures returns a non-zero fixtures count when at least one fixture is invalid; writeFixtures returns written: [] when any fixture has a non-repairable error.

Verification

• node --check passes on all modified .mjs/.js files.
• checkBarrelExports verified via inline tests: passes on the real tree, detects missing and extra exports.
• node --test fixtures tests for scripts/fixtures.d.ts declares parseRustTickVectors returning null but no test covers the unparseable-source branch #1197 and scripts/fixtures.d.ts and scripts/fixtures.js disagree on whether checkFixtures can report a non-zero fixture count on error #1199 pass (6/6).
• Config tests (packages/config: check-shared-config.mjs does not verify the exports listed in src/index.ts #1194, packages/config: check-shared-config.mjs has no test for the EXEMPT_WORKSPACES deny-by-default rule #1198) use vitest which is not installed in this environment; syntax verified, logic confirmed via inline tests.

Files changed

• packages/config/scripts/check-shared-config.mjs — barrel export check + exempt parameter threading
• packages/config/scripts/__tests__/check-shared-config.test.mjs — barrel export tests + deny-by-default exemption tests
• scripts/fixtures.d.ts — JSDoc documenting checkFixtures/writeFixtures error semantics
• scripts/__tests__/fixtures.test.js — parseRustTickVectors null contract tests + error semantics tests