1.2.5 — Fabric — Recommended imports, accessor and persistence fixes

This update moves recommended migration onto the existing batch transfer, strengthens Fabric accessor lifetimes and persistence handling, and shortens hopper failure backoff.

• Recommended migration now runs through the batch transfer task. Suggested quantities, paging, stopping, and continuing after closing the screen behave like manual batch transfer; the old standalone migration engine has been removed.
• Recommendations are limited to items that the current batch route can actually move. Large networks are no longer blocked by unrelated 4096-variant limits.
• Fabric batch export now performs at most 64 insert attempts or 64 slot visits per step. Inefficient third-party storage cannot loop without bound inside one tick; remaining items continue on later ticks.
• Fabric accessors use a binding lease for their storage views. Old Storage and StorageView handles no longer read or write the previous volume after unbinding, rebinding, reloading, or removing the accessor.
• Shutdown now performs a bounded final snapshot wait and records the last successful generation. Timeouts cannot hang the server indefinitely, but the newest generation is not guaranteed to persist; logs and diagnostics report dirty state, last successful generation/time, and failure reason.
• Non-atomic filesystems retain at most two verified backups after a successful install. Startup tries backups from newest to oldest, so a damaged newest backup can still fall back to the next valid one.
• The hopper failure backoff default changed from [20, 40, 100, 200, 400] to [20, 40, 80, 120, 200], reducing the longest wait from about 20 seconds to about 10 seconds. Existing TOML values are not rewritten automatically; edit hopper.failureCooldownTicks if you want the new default.

Back up the world before updating. Minecraft 1.20.1 and Tom's Simple Storage 1.7.1 are required, and client/server DSC versions must match. 1.2.5 still uses a single SavedData file and does not yet provide per-record corruption isolation; a damaged record can make all volumes read-only. Bounded shutdown and non-atomic replacement cannot guarantee zero data loss. Cross-loader world conversion remains unverified.