Replaced all 688 Label_XXXX labels with semantic names:
- 122 jmp-target labels renamed with routine-specific names
(e.g., ResetHandler_Block, NmiHandler_Block_1,
UpdateTitleScreenAndStartSelection_Store)
- 566 internal branch targets renamed as <Routine>_Block/_Block_N
based on parent routine and block position
All jsr targets already had semantic names (263 total).
Build verified byte-identical. verify_pass1.py passes with 'canoni'
comment format.
Updated TODO.md: removed Donkey Kong Jr. from Label_ residue table.