test: audit competitor behavior across JS and Rust

.github/workflows/js.yml

@@ -267,6 +267,7 @@ jobs:
           "
           node --test js/tests/node-terminal-artifacts.mjs
           node --test js/tests/node-commonjs-entry.mjs
+          node --test js/tests/node-process-regressions.mjs
 
   release:
     name: Release JavaScript package

.prettierignore

@@ -19,3 +19,9 @@ dev/log
 # quoted evidence (prettier re-parses the ambiguous nested backticks in
 # issue-166/upstream-issue.md and destroys the list it is quoting).
 docs/case-studies
+# Generated newline-delimited ledgers; one compact record per upstream test
+# keeps exhaustive provenance reviewable without 100k lines of JSON layout.
+js/tests/competitor-dispositions.jsonl
+js/tests/competitor-decisions.jsonl
+rust/tests/competitor_dispositions.jsonl
+rust/tests/competitor_decisions.jsonl

README.md

@@ -38,7 +38,16 @@ JavaScript and Rust releases are independent:
 
 ## Development
 
-Run language-specific checks from the language folders:
+Both maintained language implementations carry pinned, executable competitor
+compatibility corpora with explicit missing-feature ledgers:
+
+- [JavaScript competitor test audit](./js/docs/COMPETITOR_TEST_AUDIT.md)
+- [Rust competitor test audit](./rust/docs/COMPETITOR_TEST_AUDIT.md)
+
+Run the focused suites with `bun run test:competitors` in `js/` and
+`cargo test --test competitor_compatibility` in `rust/`.
+
+Run all language-specific checks from the language folders:
 
 ```bash
 cd js