chore: port PR #278 (Ironwood/NU6.3) into the faucet branch

.config/nextest.toml

@@ -3,4 +3,14 @@ fail-fast = false
 
 [profile.ci]
 fail-fast = false
-default-filter = 'not (test(zebra) | test(zaino))'
+# These test binaries spawn real zcashd/zebrad/zainod/lightwalletd/devtool
+# processes, which the CI image does not provide. Exclude by binary_id, not
+# by test-name substring: name filters both missed binary-requiring tests
+# with unconventional names and silently hid pure unit tests that happened
+# to mention a binary in their name.
+default-filter = '''
+not (
+  binary_id(zcash_local_net::integration)
+  | binary_id(regtest-launcher::e2e)
+)
+'''

.github/workflows/ci-pr.yaml

@@ -43,19 +43,18 @@ jobs:
       - name: Cache cargo
         uses: Swatinem/rust-cache@v2
 
-      - name: Install just
-        uses: extractions/setup-just@v2
-
       - name: Install cargo-binstall
         uses: taiki-e/install-action@v2
         with:
           tool: cargo-binstall
 
       - name: Install cargo-check-external-types
-        run: cargo binstall cargo-check-external-types -y --force
+        # Pinned to match PINNED_NIGHTLY in workbench/src/main.rs (nightly-2025-10-18,
+        # rustdoc JSON format 56). 0.5.0 requires format 57; bump both together.
+        run: cargo binstall cargo-check-external-types@0.4.0 -y --force
 
       - name: Run checks
-        run: just check-external-types
+        run: cargo +nightly-2025-10-18 run --release -p workbench -- check-external-types
 
   reject-trailing-whitespace:
     uses: ./.github/workflows/trailing-whitespace.yaml

.github/workflows/test.yaml

@@ -57,19 +57,13 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v6
 
-      - name: create binaries dir
-        run: mkdir -p ./test_binaries/bins
-
-      - name: Symlink lightwalletd and zcash binaries
-        run: ln -s /usr/bin/lightwalletd /usr/bin/zcashd /usr/bin/zcash-cli ./test_binaries/bins/
-
       - name: Download archive
         uses: actions/download-artifact@v6
         with:
           name: nextest-archive
 
       - name: Run tests
         run: |
-          cargo nextest run --verbose --profile ci --retries 2 -E 'not binary_id(regtest-launcher::e2e)' --archive-file nextest-archive.tar.zst \
+          cargo nextest run --verbose --profile ci --retries 2 --archive-file nextest-archive.tar.zst \
             --workspace-remap ./ ${{ env.NEXTEST-FLAGS }}
 

.github/workflows/trailing-whitespace.yaml

@@ -11,5 +11,8 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v6
 
+      - name: Cache cargo
+        uses: Swatinem/rust-cache@v2
+
       - name: Reject trailing whitespace
-        run: ./utils/trailing-whitespace.sh reject
+        run: cargo run --release -p workbench -- trailing-whitespace reject

CLAUDE.md

@@ -3,6 +3,16 @@
 This file collects conventions that AI contributors (and humans
 reviewing AI-authored work) should apply to PRs in this repository.
 
+## Tool selection
+
+Always prefer Rust-native tools in domains where they are designed to
+operate. Dependency and manifest changes go through `cargo add` /
+`cargo remove` / `cargo update`. Code navigation and refactors go
+through rust-analyzer. Verification goes through `cargo check` /
+`cargo clippy` / `cargo fmt` / `cargo nextest`. Do not reach for
+Python, sed, or regex sweeps over Rust source or `Cargo.toml` when a
+Rust tool covers the job.
+
 ## Code-review checklist: bugs Rust won't catch
 
 Memory-safety guarantees and the type system catch a lot, but the

CONTEXT.md

@@ -0,0 +1,93 @@
+# infras
+
+Test infrastructure for the Zcash ecosystem: harnesses that launch and drive
+local Zcash networks (validators, indexers, clients) for integration testing.
+
+## Language
+
+**Validator**:
+A full-node process that maintains chain state and serves the node RPC
+(zebrad, or legacy zcashd).
+_Avoid_: node, daemon, full node
+
+**Indexer**:
+A process that consumes a Validator's data and serves the light-client
+gRPC protocol (zainod, or legacy lightwalletd).
+_Avoid_: proxy, server
+
+**Wallet**:
+A light-client process the harness manages alongside the Validator and
+Indexer: restored from a seed, synced through an Indexer, driven to
+send and shield, and queried for balances and addresses. The harness
+actuates every Wallet through one generic interface; each
+implementation lives with its own binary (zcash-devtool, zingo-cli).
+_Avoid_: client (the superseded name), lightclient
+
+**Legacy stack**:
+zcashd (Validator) and lightwalletd (Indexer). Opt-in only, scheduled for
+simultaneous removal; neither is part of the harness's future.
+_Avoid_: deprecated components, old stack
+
+**Core stack**:
+zebrad (Validator) and zainod (Indexer) — the components the harness is
+built around and that survive Legacy-stack removal.
+_Avoid_: new stack, default stack
+
+**Compatibility conf**:
+The `zcash.conf`-format file lightwalletd parses to discover its backend
+Validator. Owned by the Legacy stack: zcashd uses it as its own process
+config, and zebrad produces one only to serve lightwalletd. Dies with the
+Legacy stack.
+_Avoid_: zcashd config (when the lightwalletd-facing file is meant)
+
+**Devtool contract**:
+The behavioral interface the harness relies on from the zcash-devtool
+binary: its CLI surface, its output formats, and the activation-heights
+schema. A process boundary pinned by tests against the real binary — never
+a Cargo dependency.
+_Avoid_: devtool API, devtool dependency
+
+**Canonical heights**:
+The single regtest activation-heights shape the harness ships as its
+default for launching Validators, validates, and golden-tests: every
+network upgrade the Devtool contract knows about activates at height 2.
+Exactly one shape exists per release; it advances in lockstep when a new
+upgrade is adopted, and older shapes live only in older releases. Any
+other shape is configured on the Validator alone; every other component
+receives [[Validator heights]].
+_Avoid_: all-at-2 (informal), custom heights, partial activation
+
+**Front**:
+The transparent TCP relay that is the canonical public endpoint of one
+Backend listener. It binds `127.0.0.1:0` before the Backend starts,
+every published port and address accessor returns it, and the
+Backend's real endpoint is never published — so all clients, the
+harness's own launch-time clients included, cross the Front for the
+Backend's entire networked lifetime. A Front carries at most one
+registered observer; with none it is pure passthrough.
+_Avoid_: proxy (bare), tap (the observer is the tap; the Front is the
+endpoint)
+
+**Backend**:
+A managed network service as the Front machinery sees it: start/stop
+lifecycle, log access for readiness parsing, and — once ready — raw
+listener endpoints as socket addresses. Processes are the only
+implementation today; the contract deliberately fits a future
+container whose endpoints are published host mappings.
+_Avoid_: process (when the abstraction is meant), node
+
+**Indexer convergence**:
+The moment the Indexer's view of the chain includes the Validator's
+tip. Mining returns as soon as the Validator has the blocks; the
+Indexer catches up on its own cadence, so anything that reads through
+the Indexer right after mining must wait for convergence rather than
+poll around the gap.
+_Avoid_: indexer catch-up, tip lag (as names for the barrier)
+
+**Validator heights**:
+Activation heights whose provenance is a query of the running Validator —
+the only form in which any non-Validator component may hold regtest
+heights. The Validator is configured with heights exactly once, at
+launch; the Indexer and the wallet client derive theirs from it, and
+supplying heights to those components by hand is unrepresentable.
+_Avoid_: provider heights, custom heights, caller heights