Cardano Updates

Use the hydra-github-bridge SSE endpoint for real-time build status
detection instead of polling the GitHub API. Reduces wait time from
minutes (poll interval) to seconds (event-driven).

Tested end-to-end in PR #241 — all validation jobs passed.

Use the hydra-github-bridge SSE endpoint for real-time build status
detection instead of polling the GitHub API. Reduces wait time from
minutes (poll interval) to seconds (event-driven).

Tested end-to-end in PR #241 — all validation jobs passed.

Cloudflare now bypasses cache for /status/* paths, enabling real-time
SSE event delivery.

SSE through Cloudflare buffers events. Now the script polls the
bridge's one-shot endpoint every 120s as a safety net alongside
the SSE stream.

When Hydra resolves builds from cache, it creates only aggregate
"required" check-runs but not individual per-build check-runs.
This causes the GHA upload workflow to discover zero -env closures
and skip all container uploads.

Add a fallback path: when no Hydra check-runs ending in "-env"
are found, evaluate the store paths directly from the flake using
nix eval with extra/discover-env.nix. This ensures containers are
always uploaded regardless of Hydra's check-run behavior.

Also install Nix and checkout the repo in the Discover step to
support the fallback evaluation.

Move the iog-libs.nix sync comment from inside the shell heredoc
(where it breaks line continuation and triggers SC2215) to a Nix
comment above the writeShellApplicationWithRuntime block.

Extract the duplicated IOG dependency lists from dynamic.nix,
static.nix, cross-js.nix, and cross-windows.nix into a single
iog-libs.nix file. This eliminates manual synchronization when
adding new libraries (e.g., lmdb was previously missing from
cross-compilation targets) and provides a canonical source of
truth for IOG-specific dependencies.

The centralized file categorizes dependencies into:
- crypto: libblst, libsodium-vrf, secp256k1 (all shell types)
- data: lmdb (dynamic/static only)
- tools: cbor-diag, cddl, gh, icu, jq, yq-go (dynamic/static)
- cross-tools: cbor-diag, cddl (cross-compilation targets)

Each consumer imports iog-libs.nix and transforms as needed
(e.g., static.nix passes static=true to resolve static-* variants).

Addresses #56

ouroboros-consensus depends on cardano-lmdb which requires the lmdb
system library (pkg-config: lmdb>=0.9 && <0.10). Since UTxO-HD was
integrated in Cardano Node 10.4.1, lmdb is required for all Cardano
development.

Adds lmdb to dynamic shells and static-lmdb (static-only build via
Makefile ILIBS patching, matching nixpkgs isStatic pattern) to static
shells. The wrapped-cabal in static.nix gets the corresponding -L flag
so GHC finds the static library.

Closes #218
Supersedes #221

ouroboros-consensus depends on cardano-lmdb which requires the lmdb
system library (pkg-config: lmdb>=0.9 && <0.10). Since UTxO-HD was
integrated in Cardano Node 10.4.1, lmdb is required for all Cardano
development.

Adds lmdb to dynamic shells and static-lmdb (static-only build via
Makefile ILIBS patching, matching nixpkgs isStatic pattern) to static
shells. The wrapped-cabal in static.nix gets the corresponding -L flag
so GHC finds the static library.

Closes #218
Supersedes #221

GNU config.sub normalises to "aarch64-apple-darwin" while Apple's
LLVM toolchain (and nix cc-wrapper's @defaultTarget@) uses
"arm64-apple-darwin". Older GHC versions pass --target=aarch64-apple-darwin
which triggers a noisy warning from the cc-wrapper's
add-clang-cc-cflags-before hook on every compiler invocation.

The warning is harmless — clang handles both triples identically — but
it pollutes stderr and causes thousands of GHC testsuite failures due
to unexpected compiler output.

Set NIX_CC_WRAPPER_SUPPRESS_TARGET_WARNING=1 in the env script before
sourcing stdenv/setup to suppress this warning.