Delegate accounts larger than 10 KiB in MagicBlock Protocol v2 #80

Goal

Allow an owning program to delegate an existing account larger than 10 KiB (10,240 bytes) through MagicBlock Protocol v2 without losing its data.

Why

The SDK delegation helper creates a temporary buffer matching the account's full size in one CPI. That allocation prevents the normal flow from handling large accounts. The experimental v2 delegation path still expects a prepared buffer; it does not by itself resolve the SDK-side allocation.

Scope

• Support large-account delegation through the v2 program and owning-program SDK helpers, including delegation with actions. Account for temporary-buffer setup as well as the delegation instruction itself.
• Preserve account bytes and the expected ownership, lamport, and delegation-state transitions. Support accounts just above 10 KiB and accounts requiring more than one allocation increment.
• Coordinate the lifecycle changes with Streamline the MagicBlock Protocol v2 delegation account lifecycle #203. Keep large commit/finalize handling in Support large-account commits in MagicBlock Protocol v2 #191 rather than duplicating that work here.

This is v2 work under #132. Keep v1 interfaces unchanged.