Fix shield pending expiry using L2 checkpoint height instead of Bitcoin height

P2P shield commitment broadcast + retry for tree convergence

L2 per-node direct fee distribution, key index stability, settlement fee fixes

Fix inverted pending shield cleanup: delete finalized, not unfinalized

Fix checkpoint pipeline self-healing after node restarts

Soak test: triple-snapshot tree check, no-inject mode, high-traffic mode

Fix L2 balance query case mismatch: 'Active' → 'active'

Add seed-test-balance admin endpoint, wire L2 balance seeding into soak test

Fix phantom note divergence on restart, add stale pending shield cleanup

Add audit/report files and build dirs to .gitignore

Add simulate-unshield endpoint, fix ghost-core static asserts, improve soak test

Add client-side cooldown to tree sync requests

Remove Ladder Script references from ghost-core, enable signet min-difficulty

Fix L2 note gap recovery when checkpoints survive but notes are lost

Add temporary landing page for signet testing period