Cardano Updates

cardano-node 10.7.x's lsm-tree dependency pulls in libsnappy.  On darwin
the linker picks up libsnappy.dylib from the nix store unless we add a
-L for static-snappy first.  packaging.nix's checkPhase rejects the zip
when binaries reference /nix/store at runtime ("still depends on nix
store").

Mirror the fix already present in cardanoNodePrePkg (added in 15b8d0d
back when the pre slot was 10.7.0).

cardano-node 10.7.x's ouroboros-consensus pulls in proto-lens-protobuf-types
and a new cardano-rpc package, both of which invoke protoc at build time
through proto-lens-setup's custom Setup.hs.  Without protoc on PATH the
build fails with 'couldn't find the executable protoc'.

The pre-release pkg already had this for proto-lens-protobuf-types since
commit f8709bd; now mirror it in the stable pkg (post-10.6.4 → 10.7.1
bump) and add cardano-rpc to both.

cardano-node 11.0.0's cabal.project pins index-state
'cardano-haskell-packages 2026-05-02T16:21:41Z'.  Our previous CHaP
input was at 2026-04-15T11:20:53Z, causing plan-to-nix to fail with
[Cabal-7159] during evaluation.  Bump to the latest CHaP commit.

10.7.1 was released 2026-04-15 as the latest stable, supplanting 10.6.4.
11.0.0 (commit 1f5588d9, 2026-05-03) is tagged but its GitHub release
is still draft; pin to the tag for early CI exposure to the next major.

Notes for downstream:
  - 10.7.1 needs a chain replay (TablesCodecVersion1 changes on-disk
    encoding); LSM Tree backend replaces LMDB on OnDisk.
  - cardano-api: submitTxToNodeLocal now returns TxSubmitResult.
  - The new linux build deps (liburing/snappy-c/protobuf) are already
    handled by the prior overlay fix.

cardano-node 10.7.0+ pulls in ouroboros-consensus:lsm, which depends on
lsm-tree (extra-libraries: snappy) and blockio-uring (extra-libraries:
uring).  Linking the fully static musl binary fails with:

  ld: cannot find -luring: have you installed the static version ?
  ld: cannot find -lsnappy: have you installed the static version ?

because nixpkgs's pkgsCross.musl64.snappy is dynamic-only by default and
pkgsCross.musl64.liburing's postInstall removes the .a unless
stdenv.hostPlatform.isStatic (which is false for plain musl64).

Add musl-conditional overrides to the nixpkgs overlay:

  - snappy: force -DBUILD_SHARED_LIBS=OFF (matches upstream cardano-node's
    nix/pkgs.nix).
  - liburing: replace postInstall to delete .so* instead of .a, while
    keeping the example-binaries copy to $bin.

This unblocks cardano-tools-pre-static (and -static-arm64).  The
cardano-tools-static (10.6.4) and pruned-cardano-tools-static targets are
unaffected because they don't pull in lsm-tree.

Verified: nix build .#packages.x86_64-linux.cardano-tools-pre-static
on a real x86_64-linux NixOS host now succeeds and produces
x86_64-linux-cardano-node-pre-10.7.1-045bc18.zip.