fix: minimize deploy cutover downtime

.gitea/workflows/ci.yaml

@@ -78,6 +78,11 @@ jobs:
                 rm -rf "${LIVE}/.next" || true
                 mv "${LIVE}/.next.prev" "${LIVE}/.next" || true
               fi
+              if [ -d "${LIVE}/node_modules.prev" ]; then
+                echo "Rolling back node_modules to previous artifact..." >&2
+                rm -rf "${LIVE}/node_modules" || true
+                mv "${LIVE}/node_modules.prev" "${LIVE}/node_modules" || true
+              fi
               pm2 restart next --update-env 2>/dev/null || pm2 start pnpm --name "next" -- start 2>/dev/null || true
             fi
             if [ -n "${STAGE}" ] && [ -d "${STAGE}" ]; then
@@ -169,17 +174,14 @@ jobs:
             exit 1
           fi
 
-          echo "Cutover: stop service and swap .next..."
-          CUTOVER_STARTED=1
-          pm2 stop next --kill-timeout 10000 || true
-
           cd "${LIVE}"
           echo "Hard reset live tree to origin/main (no nuclear src wipe)..."
           git reset --hard origin/main
           # Keep env, uploads, and deps we are about to replace from stage.
           git clean -fd \
             -e .env -e .env.local -e .env.production -e .env*.local \
-            -e storage -e public/cache -e node_modules -e .next -e .next.prev
+            -e storage -e public/cache \
+            -e node_modules -e node_modules.prev -e .next -e .next.prev
 
           if ! git diff --exit-code HEAD -- src >/dev/null; then
             echo "ERROR: live src/ still differs from HEAD after reset:" >&2
@@ -188,18 +190,6 @@ jobs:
           fi
           echo "Verified live src/ matches HEAD"
 
-          # Save current .next as backup before swapping (kept until health check passes).
-          if [ -d .next ]; then
-            mv .next .next.prev
-          fi
-          mv "${STAGE}/.next" .next
-
-          # Use the exact node_modules the stage build resolved against.
-          rm -rf node_modules
-          mv "${STAGE}/node_modules" node_modules
-
-          sudo chown -R "${DEPLOY_USER}:${DEPLOY_GROUP}" "${LIVE}" 2>/dev/null || true
-
           # Next.js prefers an already-set process PORT over .env. PM2 may still
           # have PORT=3000 from an older start, while .env (and nginx) expect 3002.
           # Export PORT before start so the process matches health checks.
@@ -220,14 +210,25 @@ jobs:
             fi
           }
 
-          echo "Starting PM2 with a clean PORT=${PORT} listener..."
+          echo "Cutover: atomically swap artifacts and restart on PORT=${PORT}..."
+          CUTOVER_STARTED=1
+          pm2 stop next --kill-timeout 10000 || true
+
           cd "${LIVE}"
-          # Cutover already stopped the app, but failed deploys can leave orphans
-          # on 3002 (or an old PM2 env still bound to 3000).
-          pm2 stop next --kill-timeout 10000 2>/dev/null || true
+
+          # Rename both current artifacts so cutover and rollback stay fast.
+          if [ -d .next ]; then
+            mv .next .next.prev
+          fi
+          mv "${STAGE}/.next" .next
+          if [ -d node_modules ]; then
+            mv node_modules node_modules.prev
+          fi
+          mv "${STAGE}/node_modules" node_modules
+
           free_tcp_port "${PORT}"
           free_tcp_port 3000
-          sleep 1
+          echo "Starting PM2 with a clean PORT=${PORT} listener..."
           pm2 delete next 2>/dev/null || true
           PORT="${PORT}" pm2 start pnpm --name next -- start
           pm2 save 2>/dev/null || true
@@ -262,8 +263,8 @@ jobs:
             exit 1
           fi
 
-          echo "Cleaning stage worktree and previous .next backup..."
-          rm -rf "${LIVE}/.next.prev"
+          echo "Cleaning stage worktree and previous artifact backups..."
+          rm -rf "${LIVE}/.next.prev" "${LIVE}/node_modules.prev"
           git -C "${LIVE}" worktree remove --force "${STAGE}" 2>/dev/null || rm -rf "${STAGE}" || true
           STAGE=""