BREAKING CHANGES: remove the Playwright integration, which ran proofs in a Node worker rather than in a browser: no @playwright/test dependency, no playwright CI job, engine, test context, or scenario runner #1414
BREAKING CHANGES:fjs/bnf/descent: match results are now the record { ast, success, idx, failure? } instead of a tuple. failure is present only on a failed match and holds the furthest position a terminal was rejected at plus the terminals expected there — a failed result's own index rewinds and cannot locate an error #1412
BREAKING CHANGES:@playwright/test moves to 1.59.1 to match the pinned Nixpkgs snapshot, which now provides the playwright CI job's browsers — the job runs in a generated Nix flake instead of installing them #1409
fjs/ci: generate one self-contained nix/generated/<job>/flake.nix per canonical Node job, pinning an exact Nixpkgs commit; npm run ci-update writes them without running Nix #1398
BREAKING CHANGES:range_map's exported get and fromRange take the map/default-value first and the queried number/range last. Add fjs/types/range_set, a boolean-valued range_map wrapper #1402
BREAKING CHANGES: decouple the FJS MCP server from CAS: generic MCP moves fjs/mcp/ → fjs/protocol/mcp/, JSON-RPC moves fjs/media/json/rpc/ → fjs/protocol/json_rpc/, and the CAS tool registry moves fjs/cas/mcp/ → fjs/mcp/cas/ (with fjs/cas/evo/mcp/ → fjs/mcp/evo/); the server's new composition root lives at fjs/mcp/#1401
fjs/media/nix: add a minimal checked Nix eDSL and deterministic chunk serializer #1397
fjs/effects/node: BREAKING CHANGES: detect Deno as the new 'deno'Engine variant and make external tests on Node 22–25 use the inline expectFailure compatibility strategy #1393
package.json: drop npm-check-updates from npm run update entirely — it now only reinstalls/relocks; package.json devDependency bumps are manual for now #1392
package.json: pin @playwright/test exactly (=1.62.0) and exclude it from npm run update's npm-check-updates pass, so the pinned test runner version survives routine dependency updates #1391