[4i7]

Implements the AppInfo cache / Process lifetime detailed design.

Key changes:

• replace tracked Lazy<IAppInfo> with exact-identity Lazy<ProcessAppInfoEntry> cache entries
• add rich watcher status/generation leases and exact ProcessWatcherData unregister semantics
• publish watchers only after EnableRaisingEvents succeeds
• latch pre-publication exits and classify enable failure with a detached-handler silent probe
• validate candidate and winner generations before callback transfer
• add deterministic seams and AppInfo cache/process-generation regression coverage (Tests A-K)
• preserve regeneration through optimizer stage 10 and stage-15 lifecycle finalization
• gate validate/apply/release/upstream-regeneration workflows on the new lifetime test

Design basis: MyMix_AppInfo_Cache_Detailed_Design.md.