Fix P2AH activation, authorization, and indexing edge cases

[shuu-beep]

Summary

This patch addresses issues found while extending regression coverage around PR RavenProject#1283, while preserving the existing P2AH design and normal tested paths.

Main changes

• pre-activation and activation-context handling
• reorg/restart state consistency
• any-m-of-n wallet authorization resolution
• authorization graph processing
• P2AH address/spent index producer-consumer consistency
• strict preimage parsing
• signing sighash consistency
• wallet visibility/watch-only handling
• stress test reset-path safety

Validation

• The upstream PR HEAD was tested directly.
• The final fixed commit was tested with the same targeted A/B scenarios.
• 8 findings were reproduced on the original PR and resolved on the fixed commit.
• F-09 was not reproduced and is not presented as an original defect.
• F-06 was not applicable to an unreleased PR.
• No fixed-side regressions were observed.
• Full unit tests and relevant functional/regression tests passed.
• The v4.8.0 integration build and relevant tests passed.

Baseline

• Upstream PR HEAD: 689427739a3a460643e3d0bbddc755ae8dfe1fe4
• Fix commit: 5b893937cdce185769e1684cb1e5685707558b29

[Tylerlhess]

These are awesome catches! Thanks for understanding the heart of the feature and catching where I had missed some logic.

[shuu-beep]

Thanks! I'm glad the fix helped, and I appreciate you taking the time to review and merge it. I’d also love to see P2AH make it into main and help move Ravencoin forward.