[yyjeqhc]

Runner response, Job-update and registration fixtures repeated absent wire fields throughout ToolRuntime tests. This consolidates 58 result and 28 Job-update constructors into two test-only helpers, and routes 18 registrations through the existing runner_registration helper.

Call sites still supply exact Runner/request/Job identities, status and finished, plus all scenario-specific evidence. The helpers infer neither success nor lifecycle from exit status, preserve absent versus empty streams, and permit inconsistent inputs used by negative tests. Registration capability normalization is unchanged. No runtime implementation, tool/schema, persistence format, assertion or test case is removed.

The benefit is one place to maintain absent fields for each wire fixture, without adding production defaults, macros, generic builders or dispatch layers. The exploratory estimate was about 500 lines; the formatted result is 559 Rust lines removed.

Metric	Before	After	Net change
ToolRuntime production Rust (estimated separation)	92,729	92,729	0
ToolRuntime test Rust (including estimated inline tests)	164,632	164,073	-559
ToolRuntime Rust total	257,361	256,802	-559
Repository Git-tracked Rust total	928,714	928,155	-559

Counts use exact PR merge base bc63e43505f0162153950bc9ee43c3f6458b4294, physical source lines including comments/blanks, and all tracked .rs files. Dedicated test files (tests/, tests.rs, *_tests.rs) change from 145,402 to 144,843 lines. An additional 19,230 lines are estimated from explicit #[cfg(test)]/#[cfg(all(test, ...))] item spans, unchanged by this PR. The production/test partition is approximate; all total and delta counts are exact. No generated frontend/documentation changes are included.

Validation on local macOS:

• cargo test --locked -p webcodex --lib tool_runtime::tests::: 1,590 passed, 0 failed, 0 ignored. Run before and after registration consolidation at default concurrency.
• cargo test --locked -p webcodex --lib tool_runtime::tests:: --no-run: passed without warnings after final unused-import/empty-wrapper cleanup.
• cargo fmt --all -- --check and git diff --check: passed.
• Migration checked every omitted result/Job field against the constructor's exact default and retained all other expressions. Token comparison confirms all 7,631 assertion macros in the 41 changed files are unchanged.

Risk is confined to test fixture construction. Recovery, uncertain execution, privacy, read cancellation and Job sequence scenarios remain exercised. Native Windows/Linux and optional feature configurations were not run locally; ordinary CI remains required. No services were restarted and no deployment/release is included.