Standardizes build process and adds OVERVIEW.md for each

Bomberman (U)/copilot/header.s

@@ -0,0 +1,12 @@
+; Bomberman NES - Phase 3 semantic refinement
+; Based on the user-validated Phase 2 recursive trace from NMI, RESET, and IRQ/BRK.
+; Reachable official 6502 opcodes are emitted as instructions.
+; Unreachable bytes are classified as explicit data regions.
+
+.setcpu "6502"
+.include "symbols.inc"
+.include "locals.inc"
+
+.segment "HEADER"
+InesHeader:
+    .byte $4E, $45, $53, $1A, $01, $01, $01, $00, $00, $00, $00, $00, $00, $00, $00, $00 ; ROM $000000: 4E 45 53 1A 01 01 01 00 00 00 00 00 00 00 00 00