script/test: fail-fast ordering — cheapest deterministic checks first

Reorders the gate so fmt --check, duplicate-module scan, clippy, and
doc-coverage run before the frontend build and the multi-minute test
suites. set -euo pipefail short-circuits on the first failure, so a
fmt or clippy drift now fails in seconds instead of after a 30s
frontend build.

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

script/test

@@ -11,14 +11,16 @@ export GIT_CONFIG_VALUE_0=master
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
 
-echo "=== Building frontend ==="
-if [ -d "$PROJECT_ROOT/frontend" ]; then
-  cd "$PROJECT_ROOT/frontend"
-  npm install
-  npm run build
-  cd "$PROJECT_ROOT"
+# Ordered fail-fast: cheapest deterministic checks first, slowest builds and
+# test suites last.  `set -euo pipefail` aborts at the first failure, so a fmt
+# or clippy drift never wastes time on a frontend build or a multi-minute
+# test run.
+
+echo "=== Checking Rust formatting ==="
+if cargo fmt --version &>/dev/null; then
+  cargo fmt --manifest-path "$PROJECT_ROOT/Cargo.toml" --all --check
 else
-  echo "Skipping frontend build (no frontend directory)"
+  echo "Skipping Rust formatting check (rustfmt not installed)"
 fi
 
 echo "=== Checking for duplicate module files (X.rs and X/mod.rs coexisting) ==="
@@ -42,19 +44,22 @@ if [ "$_dup_found" -eq 1 ]; then
   exit 1
 fi
 
-echo "=== Checking Rust formatting ==="
-if cargo fmt --version &>/dev/null; then
-  cargo fmt --manifest-path "$PROJECT_ROOT/Cargo.toml" --all --check
-else
-  echo "Skipping Rust formatting check (rustfmt not installed)"
-fi
-
 echo "=== Running cargo clippy ==="
 cargo clippy --manifest-path "$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"
+  npm install
+  npm run build
+  cd "$PROJECT_ROOT"
+else
+  echo "Skipping frontend build (no frontend directory)"
+fi
+
 echo "=== Running Rust tests ==="
 cargo test --manifest-path "$PROJECT_ROOT/Cargo.toml" --bin huskies
 cargo test --manifest-path "$PROJECT_ROOT/Cargo.toml" -p source-map-gen