Add custom architecture basic block analysis

[tinysec]

Summary

• wire managed custom architecture basic-block analysis callbacks
• replace the detached context DTO with a native-owned typed analysis context
• expose analysis inputs, output mutation methods, block creation, and temporary references
• fix the native context layout by including functionArchContext

Verification

• dotnet build --configuration Release (0 warnings, 0 errors)
• targeted core-created-context E2E: 1/1
• full external E2E: 288/288