fix: build frontend before cargo in script/test (merge gate self-heal)

Story 1113 added `#[derive(RustEmbed)] #[folder = "../frontend/dist"]`
plus a unit test that calls `EmbeddedAssets::iter()`.  The macro only
generates `iter()` when the folder exists at compile time, so the Rust
build now has a hard compile-time dependency on `frontend/dist/`.

`script/test` ran `cargo clippy` (line 48) before the frontend build
(line 53+).  In a fresh merge worktree with no `frontend/dist/`, clippy
failed immediately on the `iter()` call and the script exited before
`npm run build` ever ran — the gate could never self-heal.  Blocked
1116's merge today; would block every future merge.

Move the frontend build above all cargo invocations.  Verified by
running script/test in a fresh worktree with `node_modules` and
`frontend/dist` removed: 385/385 frontend tests + cargo tests pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

script/test

@@ -11,10 +11,12 @@ export GIT_CONFIG_VALUE_0=master
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
 
-# Ordered fail-fast: cheapest deterministic checks first, slowest builds and
-# test suites last.  `set -euo pipefail` aborts at the first failure, so a fmt
-# or clippy drift never wastes time on a frontend build or a multi-minute
-# test run.
+# Ordered fail-fast: cheapest deterministic checks first.  The frontend build
+# must run *before* anything that compiles Rust, because story 1113 introduced
+# a compile-time dependency on `frontend/dist/` via `rust-embed` — a fresh
+# merge worktree without that directory will fail `cargo clippy` on
+# `EmbeddedAssets::iter()` before the frontend build has a chance to populate
+# it.  `set -euo pipefail` aborts at the first failure.
 
 echo "=== Checking Rust formatting ==="
 if cargo fmt --version &>/dev/null; then
@@ -44,12 +46,6 @@ if [ "$_dup_found" -eq 1 ]; then
   exit 1
 fi
 
-echo "=== Running cargo clippy ==="
-cargo clippy --manifest-path "$PROJECT_ROOT/Cargo.toml" --all-targets --all-features -- -D warnings
-
-echo "=== Checking doc coverage on changed files ==="
-cargo run --manifest-path "$PROJECT_ROOT/Cargo.toml" -p source-map-gen --bin source-map-check --quiet -- --worktree "$PROJECT_ROOT" --base master
-
 echo "=== Building frontend ==="
 if [ -d "$PROJECT_ROOT/frontend" ]; then
   cd "$PROJECT_ROOT/frontend"
@@ -75,6 +71,12 @@ else
   echo "Skipping frontend build (no frontend directory)"
 fi
 
+echo "=== Running cargo clippy ==="
+cargo clippy --manifest-path "$PROJECT_ROOT/Cargo.toml" --all-targets --all-features -- -D warnings
+
+echo "=== Checking doc coverage on changed files ==="
+cargo run --manifest-path "$PROJECT_ROOT/Cargo.toml" -p source-map-gen --bin source-map-check --quiet -- --worktree "$PROJECT_ROOT" --base master
+
 echo "=== Running Rust tests ==="
 cargo test --manifest-path "$PROJECT_ROOT/Cargo.toml" --bin huskies
 cargo test --manifest-path "$PROJECT_ROOT/Cargo.toml" -p source-map-gen