#324 B4: forced non-zero-delta restore verifier — prove the bitmap is complete (Axis B / ADR 0025 D2)

Part of #318 (epic). Axis B, ADR 0025 D2. THE correctness gate. Depends on B2+B3.

Goal

Restore the raw-region image at a deliberately non-zero base delta and pass the full suite. This proves the relocation bitmap (B3) is complete — a delta-0 test cannot, because no word actually needs relocating so missing bits never bite (ADR 0025's stated trap).

Approach

• Load-time: map regions at a forced offset (or kernel-chosen/ASLR base), record per-region delta.
• Walk the bitmap once: for each set bit, *w += owning-region delta (cross-region pointers add the TARGET region's delta — see ADR 0025 Open questions: 2-pass or per-region bitmap split).
• Add a test harness that forces a non-zero delta.

Acceptance gate

Forced non-zero-delta restore passes the FULL suite incl. (asdf:load-system "alexandria"). Any crash/miscompare = a missing bitmap bit; fix the ledger, not the symptom. This gate must be green before B6 deletes anything.