solana: pin builder-stake's bytes, for both networks

CHANGELOG.md

@@ -25,6 +25,7 @@ All notable changes to this project will be documented in this file.
   - `sdk/shreds/go` carries the feed subscription program's `FeedDistribution` account: how much USDC one feed collected for one calendar month. The program is a second program alongside shred subscription and had nothing in this SDK, so each consumer decoded the account at fixed byte offsets itself, lake included. The account is a bytemuck Pod read here field by field, which agrees with the Pod bytes only because the field order leaves no interior padding; `TestStructSizes` pins the 120-byte total and a new test pins every field against a real mainnet account. `Client` is built around one program ID and so gains no fetch method, and `DeserializeFeedDistribution` is exported for a caller that makes its own `getProgramAccounts` call. `make sdk-test` never ran `./sdk/shreds/go/...`, so this package's layout pins have never run in CI; it runs them now. (#4216)
   - The TypeScript and Python `Feed` deserializers read the RFC-28 tail and synthesize `Active` for an account that carries no status byte, matching the Rust program. New `feed_legacy` fixture covers that path alongside the updated `feed` fixture.
 - Solana programs (`solana/`)
+  - `builder-stake` is covered by the reproducible-build checksums, for both networks. It was absent from both files since it was added, and `shasum -c` checks only the files it names, so the verification passed while pinning nothing about this program's bytes.
   - `builder-stake` carries its own instruction builders in `instruction::builders`, moved out of the test harness now that a caller outside the crate needs them. Each one fixes the account order the processor expects, so a change there has one place to update rather than one per caller.
   - `builder-stake` exposes its `processor` module and `try_process_instruction` under the existing `entrypoint` feature, so a test in another crate can load the program natively through `processor!` rather than building it to BPF first. `doublezero-serviceability` already exposes its own for the same reason. The crate's own tests still run against the `.so`, and nothing is exposed to a consumer that does not ask for the feature.
   - `builder-stake` holds a bond for six months and returns the excess after. The first bond starts the hold and a later one does not restart it, so a repricing that forces a top-up cannot push a builder's withdrawal date out. `Withdraw` returns anything above the stake's requirement to a token account the builder names, and refuses both before the hold elapses and below the requirement, which is what stops a builder walking its bond out from under a live feed. The hold is 180 days rather than calendar months, because a month has no fixed length and the alternative is calendar arithmetic onchain to move a one-off boundary by at most three days. A stake that has never been bonded has no hold, and a zero expiry means the hold has not started rather than that it ended in 1970. Every instruction taking a stake checks the account is at the address its own fields derive, which the zero-copy reader does not do. A `SetHoldExpiry` instruction lets a devnet demo show a withdrawal without waiting: it exists in every build and refuses outside a `development` one, rather than sitting behind a `#[cfg]` that would give the two binaries different instruction encodings for the same bytes.

solana/programs/sha256sums_development.txt

@@ -1,2 +1,3 @@
+98faedb2f761d02a2e1577c7c940baa48129f93c59cf63f3bc7a148346edcc1e  artifacts-development/doublezero_builder_stake.so
 ebfa651fc897ab8b5f9d4aa135fdd9e88db94dea08803e233ddb367e9314307c  artifacts-development/doublezero_passport.so
 ec0407be6c5fa00ced5963d7d03a7a8e0f4e75fed6330261b318997112e8cb8c  artifacts-development/doublezero_revenue_distribution.so

solana/programs/sha256sums_mainnet_beta.txt

@@ -1,2 +1,3 @@
+84d63121129a8a6b85fb4b9cf4f6409e25c1bf812879e76037afc3490453b06e  artifacts-mainnet-beta/doublezero_builder_stake.so
 d7c9e08b0c50970a9ffdaca384969758ec974a4768c98208f83c0f32de3dd016  artifacts-mainnet-beta/doublezero_passport.so
 99d4b7fd904adcd0ef028cbdc99f6b1e693d8f8f4121b4d75fe101a6fbde5c1a  artifacts-mainnet-beta/doublezero_revenue_distribution.so