Add deploy.sh for repeatable VPS deploys

One-command deploy: maintenance mode, checkout ref (branch or tag), conditional
composer install / npm build (only when their inputs changed), migrate, cache
rebuilds, queue restart, back up. Aborts and stays in maintenance mode on
failure. Mirrors docs/ops/deployment.md §8.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

deploy.sh

@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+#
+# FuelAlert deploy script — run on the VPS from the project root:
+#
+#   ./deploy.sh            # deploy the latest main
+#   ./deploy.sh v0.1.3     # deploy a specific tag
+#
+# It puts the site in maintenance mode, updates the code, runs migrations and
+# cache rebuilds, restarts the queue, then brings the site back up. composer
+# install and npm build only run when their inputs actually changed, so most
+# deploys skip them. If any step fails the script aborts and the site stays in
+# maintenance mode on purpose — fix the issue, then re-run.
+#
+# See docs/ops/deployment.md for first-time setup and troubleshooting.
+set -euo pipefail
+
+cd "$(dirname "$0")"
+
+REF="${1:-main}"
+echo "==> Deploying ref: ${REF}"
+
+# Remember the current commit so we can see what changed after checkout.
+BEFORE="$(git rev-parse HEAD)"
+
+echo "==> Maintenance mode on"
+php artisan down --retry=15
+
+git fetch --tags --prune origin
+git checkout "${REF}"
+
+# Fast-forward to the remote only when on a branch (a tag leaves a detached HEAD).
+if git symbolic-ref -q HEAD >/dev/null; then
+    git pull --ff-only
+fi
+
+AFTER="$(git rev-parse HEAD)"
+CHANGED="$(git diff --name-only "${BEFORE}" "${AFTER}" || true)"
+
+# Reinstall PHP deps only if the lockfile moved.
+if grep -q '^composer\.lock$' <<<"${CHANGED}"; then
+    echo "==> composer.lock changed — installing PHP deps"
+    composer install --no-dev --optimize-autoloader
+else
+    echo "==> composer.lock unchanged — skipping composer install"
+fi
+
+# Rebuild the Vue SPA only if frontend sources or the JS lockfile moved.
+if grep -qE '^(package(-lock)?\.json|vite\.config\.|resources/(js|css)/)' <<<"${CHANGED}"; then
+    echo "==> Frontend changed — rebuilding SPA"
+    npm ci
+    npm run build
+else
+    echo "==> No frontend changes — skipping npm build"
+fi
+
+echo "==> Running migrations"
+php artisan migrate --force
+
+echo "==> Rebuilding caches"
+php artisan config:cache
+php artisan route:cache
+php artisan view:cache
+php artisan event:cache
+
+echo "==> Restarting queue workers"
+php artisan queue:restart
+
+echo "==> Maintenance mode off"
+php artisan up
+
+echo "==> Deploy complete"
+php artisan about