- Rewrite apps/nexus with modular architecture:
Config, Http, Errors, Parser, Router, Handlers, Server, Main
- Use algebraic enums for ParseResult/FileResult/HttpError
- Thread-pool server via Channel<ConnectionTask> and spawn
- Fix C backend type ordering for generic struct instances
(Array_T, Iter_T) and algebraic enum struct payloads
- Collect Slice_T types from struct fields and enum payloads
- Fix match lowering for simple enums (direct value compare)
- Resolve match expression return type from first arm
- Infer element type for for-in over Array<UserStruct>
- Preserve generic type args in field access resolution
- Add fflush to PrintLine/Print for immediate server logs
- Add modern_features golden regression test
- Regenerate golden expected.c files
- Fix lexer unterminated char error test (was treating 'a as lifetime)
- Fix parser test sample.bux path for root-dir execution
- Add bux_system() to runtime.c and run command to selfhost CLI
- Switch bux_alloc from malloc to calloc for zero-init
- Fix module flattening in Cli_Check/Cli_Compile to scan full decl list
- Make test passes fully, selfhost builds successfully