createSubject hook unblocks JWT-bearer connectors

Patch Changes

• ed811f4: Update the optional AI SDK peer dependency range to accept the ai@7.0.0 beta line.
• b1c1606: Add a context-aware createSubject hook to connect() from @vercel/connect/eve. The new createSubject?: (principal, ctx) => ConnectTokenSubject option receives both the framework-resolved principal and Eve's per-connection authorization context (currently the declared server url), unblocking jwt-bearer-style connectors whose subject/assertion needs more than the principal — custom claims, the connection URL, or an audience derived from it. The adapter now threads the connection context Eve already passes to getToken / startAuthorization / completeAuthorization (previously dropped) into subject resolution, and the context type is exported as EveConnectionAuthorizationContext. Precedence is createSubject > principalToSubject > default principal mapping; principalToSubject keeps working but is now deprecated in favor of createSubject.