fix(token-guard): word-boundary match for sensitive env names (sync from template@aeac8c1)

Author: jdalton

.claude/hooks/token-guard/index.mts

@@ -120,9 +120,19 @@ type ToolInput = {
 const hasRedaction = (command: string): boolean =>
   REDACTION_MARKERS.some(re => re.test(command))
 
+// Word-boundary match so `PASS` doesn't fire on `PATHS-ALLOWLIST` and
+// `AUTH` doesn't fire on `AUTHOR`. Env-var-style boundaries treat `_`
+// as a separator (so `ACCESS_TOKEN` matches `TOKEN`) but require a
+// non-alphanumeric character on each end (so `PATHS` doesn't match
+// `PASS`). The pre-fix substring match created false positives
+// whenever a path name happened to contain a sensitive keyword as a
+// literal substring.
+const sensitiveEnvBoundaryRes = SENSITIVE_ENV_NAMES.map(
+  frag => new RegExp(String.raw`(?:^|[^A-Z0-9])${frag}(?:[^A-Z0-9]|$)`),
+)
 const referencesSensitiveEnv = (command: string): boolean => {
   const upper = command.toUpperCase()
-  return SENSITIVE_ENV_NAMES.some(frag => upper.includes(frag))
+  return sensitiveEnvBoundaryRes.some(re => re.test(upper))
 }
 
 const matchesAlwaysDangerous = (command: string): RegExp | null => {

.claude/hooks/token-guard/test/token-guard.test.mts

@@ -182,6 +182,25 @@ describe('token-guard hook', () => {
     })
   })
 
+  describe('does not false-positive on substring of sensitive name', () => {
+    // Regression: `PATHS-ALLOWLIST.YML` toUpperCase()d contains `PASS`
+    // as a substring, which the pre-fix unbounded match treated as
+    // a sensitive env reference. Word-boundary fix means `PASS` must
+    // be a standalone token (or at a `_`/`-`/`.`/`/` boundary).
+    it('paths-allowlist.yml does not trip PASS', () => {
+      assert.equal(runHook('cat .github/paths-allowlist.yml').code, 0)
+    })
+    it('AUTHOR_NAME does not trip AUTH', () => {
+      // AUTHOR ends with R; the boundary-after match correctly skips
+      // it because the next char is `_`, but `AUTH` followed by `O`
+      // (alphanumeric) is not a token boundary.
+      assert.equal(runHook('echo $AUTHOR_NAME').code, 0)
+    })
+    it('PASSAGE_TIME does not trip PASS', () => {
+      assert.equal(runHook('echo $PASSAGE_TIME').code, 0)
+    })
+  })
+
   describe('fails open on malformed input', () => {
     it('empty stdin', () => {
       const r = spawnSync(nodeBin, [hookScript], {