test(formula): use angle-bracket-free regex fixtures for the residual arm (#6223)

`(?<type>` is unquotable in a GitHub issue or PR body: the sanitizer strips `<`
followed by a letter as an HTML tag at rest, so the fixture that carries this
PR's argument would be destroyed the moment anyone pasted it. `type(` is the
same defect with the same native `SyntaxError` (`Invalid regular expression:
/type(/: Unterminated group`) and survives the round trip. Adds a `syntax[`
fixture for the third keyword while there.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MwoubC3jL271FYt9rGXwxb

Author: claude

.changeset/cel-classify-error-by-code.md

@@ -40,7 +40,7 @@ Two findings from the audit worth recording. First, the residual keyword arm was
 **not** dormant: `matches()` is an ObjectStack stdlib binding over `new
 RegExp(...)`, so an uncompilable pattern escapes as a native `SyntaxError` whose
 message echoes the pattern — and the pattern can come off the row, not just out
-of the source. `matches(record.name, record.re)` with `re = "(?<type>"` was
+of the source. `matches(record.name, record.re)` with `re = "type("` was
 graded `type`; with `"Exceeded maxAstNodes("` it was graded `bounds`. A data
 value was picking the error kind. Second, there is deliberately no `TypeError`
 arm: cel-js raises that class only from its non-evaluating `TypeChecker`, which

packages/formula/src/cel-engine.ts

@@ -942,7 +942,7 @@ function classifyCelFault(err: unknown): 'parse' | 'bounds' | 'type' | 'runtime'
  * `SyntaxError` whose message echoes the pattern (measured, #6223):
  *
  * ```text
- * matches(record.name, "(?<type>")               ->  type    (was)
+ * matches(record.name, "type(")                  ->  type    (was)
  * matches(record.name, "Exceeded maxAstNodes(")  ->  bounds  (was)
  * matches(record.name, "unexpected(")            ->  parse   (was)
  * matches(record.name, record.re)                ->  type    (was) — from a ROW

packages/formula/src/cel-error-classification.test.ts

@@ -269,11 +269,12 @@ describe('celEngine error classification (#6133)', () => {
       // read straight off the record. Before #6223 these four one-and-the-same
       // regex failures were graded `type` / `bounds` / `parse` / `type`.
       for (const [source, ctx] of [
-        ['matches(record.name, "(?<type>")', { record: { name: 'x' } }],
+        ['matches(record.name, "type(")', { record: { name: 'x' } }],
         ['matches(record.name, "Exceeded maxAstNodes(")', { record: { name: 'x' } }],
         ['matches(record.name, "unexpected(")', { record: { name: 'x' } }],
+        ['matches(record.name, "syntax[")', { record: { name: 'x' } }],
         // Not even authored: the pattern is a VALUE on the row.
-        ['matches(record.name, record.re)', { record: { name: 'x', re: '(?<type>' } }],
+        ['matches(record.name, record.re)', { record: { name: 'x', re: 'type(' } }],
       ] as Array<[string, EvalContext]>) {
         const { kind, message } = evalKind(source, ctx);
         expect(message).toContain('Invalid regular expression');