v0.22.1 — Cobol oracle cleanup

Highlights

• Fixed Cobol C-oracle span parity for fixed-format trailing trivia and guarded the normalization so free-format long-line content is not trimmed.
• Added focused Cobol cgo regression coverage and validated Cobol with both the 80-case C oracle and strict real-corpus gates.
• Split the CI build gate into faster parallel jobs and kept the post-merge main run green.
• Removed stale GLR debug/stat scaffolding, scanner/staticcheck leftovers, and cgo_harness dead helpers; C-benchmark helpers now compile only under the treesitter_c_bench tag.

Validation

• PR #155 CI green, plus local/Docker Cobol focused cgo, 80-case C oracle, and strict real-corpus validation.
• PR #156 CI green, including compile, freshness, parity_report, parity-cgo, perf-regression, race_root, race_packages, grammargen_visibility, and build.
• Main push run 28935690916 green at cead705.