ci: prune devDependencies from live tree after deploy build

.gitea/workflows/ci.yaml

@@ -171,6 +171,12 @@ jobs:
             exit 1
           fi
 
+          # Drop devDependencies before cutover: the live tree only needs runtime
+          # deps (next start). Kept after build + db:migrate, which both require
+          # devDeps (typescript, tsx). NOTE: manual tsx-driven scripts
+          # (pnpm db:migrate / pnpm jobs:worker) need a full install afterwards.
+          pnpm install --prod --frozen-lockfile
+
           cd "${LIVE}"
           echo "Hard reset live tree to origin/main (no nuclear src wipe)..."
           git reset --hard origin/main