[rust-compiler] Green the snap suite: Flow match parsing + fixture nesting

[poteto]

Summary

The "Test babel-plugin-react-compiler" CI job has failed 7 fixtures on this branch lineage since the Flow match fixtures landed. This makes it fully green so the suite can act as a hard gate again (rust burn-down failures stay in the rust job, where they belong).

• Six match-* fixtures never parsed in CI. Flow match requires hermes-parser >= 0.28 plus the enableExperimentalFlowMatchSyntax parser option; snap pinned 0.25.1 and never passed the flag (0.26 carries an incompatible draft grammar). Bump snap's hermes-parser to ^0.28.0 and pass the flag in parseInput. All six checked-in snapshots pass unchanged. babel-plugin-syntax-hermes-parser stays at 0.25.1: nothing in snap's pipeline re-parses match syntax, since hermes desugars match to an IIFE in babel mode before sprout evaluates.
• method-call-scope-merge-mutable-range-sync had a logs-only sprout divergence. It renders a bare <tr> into sprout's container; React's validateDOMNesting warning fires in exactly one of the two evaluations (warning dedup shares process state), so logs differed while rendered output was identical. Renamed tr/td to div/span: valid nesting, no warning, compiled shape unchanged (37 memo slots before and after; the snapshot diff is tag literals only).
• yarn.lock also gains the previously-missing typescript entry for the babel-plugin-react-compiler-rust workspace (pre-existing drift that any yarn install regenerates; included so it stops appearing in unrelated PRs).

Test plan

• yarn snap: 1800 Tests, 1800 Passed, 0 Failed (was 1793/1800)
• yarn snap -p 'match-*': 6/6 against checked-in snapshots, no regeneration
• yarn workspace babel-plugin-react-compiler lint: clean
• No snapshot churn beyond the one edited fixture

Second commit: the prettier check

Run prettier failed on the same lineage for two reasons: the six match fixtures fail to parse (prettier's Flow parser predates the experimental syntax; now in .prettierignore with an unignore note), and 53 files of accumulated formatting drift (now formatted, with the 45 affected fixture snapshots regenerated; churn is Input-section text only).

• node scripts/prettier/index.js: exit 0 (was 59 failures)
• yarn snap after regeneration: 1800/1800

Update (third commit): replaces the .prettierignore approach with a real formatter. A .prettierrc.js override scoped to the match-* fixture paths formats them via prettier-plugin-hermes-parser ^0.32.0 (shares the root hermes 0.32 family, minimal lockfile churn). The four fixtures whose checked-in formatting differed from hermes output are reformatted with snapshots regenerated. Both suites verified green after the swap: node scripts/prettier/index.js exit 0 with the match fixtures actually checked, yarn snap 1800/1800.