Backfill GH-0000 placeholder for SPPF sync commit references

[mikemol]

Context

Two landed commits on stage used GH-0000 as a temporary trailer placeholder:

• 683da24bd121524dc48c218d9771dfbdf181d6f0 — Optimize deadline profile site tracking cache
• 61c5d617e7b1d4e734a476adf69bc92c19f35e0f — Remove legacy wrapper scripts in favor of canonical entrypoints

GH-0000 cannot be resolved by gh issue view, which causes SPPF lifecycle validation to fail when the commit range includes those commits.

Scope

• establish a canonical issue target for the historical GH-0000 placeholders
• wire deterministic placeholder-to-issue normalization in SPPF sync extraction for the known commit SHAs
• keep validation strict for unknown placeholders (no broad silent ignore)

Acceptance

• scripts/sppf_sync.py --validate no longer fails on these two historical placeholder references
• extracted issue IDs resolve to this issue for those SHAs
• local CI replay SPPF sync range defaults match CI semantics (origin/stage..HEAD)