Implements Phase 1-3 of the RC system for automatic memory management:
- Add LuxRcHeader with refcount and type tag for all heap objects
- Add lux_rc_alloc, lux_incref, lux_decref, and lux_drop functions
- Update list allocation to use RC (lux_list_new uses lux_rc_alloc)
- List operations (concat, reverse, take, drop) now incref shared elements
- Update boxing functions (box_int, box_bool, box_float) to use RC
- String operations (concat, int_to_string, readLine) return RC strings
- File and HTTP operations return RC-managed strings
The infrastructure is ready for automatic decref insertion at scope exit
(Phase 4) and closure RC (Phase 5) in future work.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
