feat: export hook types

[kevzzsk]

Description

1. Export all lifecycle hook types (BeforeVerifyHook, AfterVerifyHook, OnVerifyFailureHook, BeforeSettleHook, AfterSettleHook, OnSettleFailureHook) and their context interfaces (aymentRequiredContext, VerifyContext, VerifyResultContext, VerifyFailureContext, SettleContext, SettleFailureContext) from @x402/core/server
2. Export ProtectedRequestHook from the HTTP layer

Why

These types were defined and used internally but not re-exported, making it impossible for consumers to type their hook implementations when using @x402/core/server.

Tests

Checklist

• I have formatted and linted my code
• All new and existing tests pass
• My commits are signed (required for merge) -- you may need to rebase if you initially pushed unsigned commits
• I added a changelog fragment for user-facing changes (docs-only changes can skip)

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[vercel]

@kevzzsk is attempting to deploy a commit to the Coinbase Team on Vercel.

A member of the Team first needs to authorize it.