SPIKE: Protocol 30 (CAP-0088)

[sisuresh]

Changes

• Bump XDR pin to stellar-xdr 03cbf40c and regen; enables MS_CLOSE_TIME on the next channel only (StellarValueSignedMsValue/StellarValueProposedMsValue + TimePointMilliseconds). curr also picks up the pin's already-live CAP-0083 STELLAR_VALUE_EMPTY_TX_SET arm (no CAP-0088 content), since both channels share one .x snapshot.
• Bring in the preprocess/post-process regen infra (stellar-xdr xfile preprocess, scripts/post-process-generated.py const-inlining, dropped -it, node:lts-alpine) — none of this existed on master yet.
• Pin XDRGEN_COMMIT to d54959f (just before Remove the JavaScript code generator xdrgen#233 removed the JS generator upstream) so make generate still works.
• Hand-patch types/curr.d.ts/types/next.d.ts for the new arms — dts-xdr's raw transform output no longer matches this repo's committed module wrapper (missing header/export/xdrHidden hack), so a full regen isn't usable; patched surgically instead, mirroring the CAP-0085 precedent.

Out-of-scope observations

• ⚠️ Remove the JavaScript code generator xdrgen#233 (merged 2026-08-18) removed the JavaScript code generator from xdrgen master entirely — breaks XDR_BASE-style regen for every consumer of this Makefile, not just this CAP. Worked around here via the XDRGEN_COMMIT pin; flagging upstream separately.
• ⚠️ dts-xdr's src/transform.js output no longer matches this repo's committed types/*.d.ts wrapper (header comment, import { Operation } from './index', export {}, xdrHidden namespace) — those aren't produced by the automated transform and must be hand-maintained. Not fixed here (out of scope); flagging for future regens.

Downstream: none yet in this stack.

[sisuresh]

⚠️ OUT-OF-SCOPE: stellar/xdrgen#233 (merged 2026-08-18, stellar/xdrgen#233) removed the JavaScript code generator from xdrgen master entirely (only go.rb remains under lib/xdrgen/generators/). This breaks make generate for every consumer of this repo's Makefile, not just CAP-0088 — unrelated to this CAP. I did NOT fix xdrgen itself; I worked around it in this repo by pinning XDRGEN_COMMIT=d54959f8949b8f354541bf0cc2af6a9130f0f3a9 (the commit immediately before #233) in the Makefile. Suggest filing an issue against stellar/xdrgen to either restore JS support or officially deprecate it so downstream consumers can migrate.

[sisuresh]

⚠️ OUT-OF-SCOPE: dts-xdr's src/transform.js (https://github.com/stellar/dts-xdr) produces a bare declare namespace xdr { ... } block, but this repo's committed types/curr.d.ts/types/next.d.ts wrap that in a header (generation-date comment, import { Operation } from './index', export {}, and an xdrHidden namespace hack for the Operation/Operation2 name collision) that the automated transform does not emit. Running make generate for the .d.ts targets today overwrites that wrapper and produces a non-module file that fails dtslint (File '.../types/curr.d.ts' is not a module). I did NOT fix dts-xdr or restore an automated wrapper-generation step; for this PR I hand-patched the existing wrapped files with the new type declarations (verified against a scratch full regen for correctness) instead of running make generate for types/*.d.ts. Future regens should do the same until dts-xdr's transform (or a wrapper script in this repo) is updated to re-emit that header.