PHLEGM v8 / Checkpoint 49 / SPC700 Compare Identifier Fix
Baseline: Checkpoint 48 (2026-1010-0913-4459).
Observed log: PHLEGM-v8-Compiler-Logs-2026-1010-0918-1647.zip.

Reported error:
src/lib/spc700-support.bi(289) error 4: Duplicated definition, difference

Change:
Renamed the local comparison intermediate `difference` to `compareDelta`
inside SnesSpcStep SPC_OP_CMP, and updated its carry/zero/negative tests.
No SPC700 micro-code definitions, execution behavior, or other source files
have been changed. This avoids the Windows FreeBASIC symbol collision.

Validation:
* Four Windows target logs (32/64bit x OpenGL/D3D11) report the same error.
* Checked replacement against exact source, operation count, CRLF policy.
* Verified ZIP integrity, archive root, unchanged member bytes and SHA256.
* Native FreeBASIC compile NOT available in this preparation environment.
* End-user packaging and ActRaiser execution NOT yet verified.
