ci: Pi-hole DNS, npm/nuget cache, serial low-RAM builds

Use LAN Traefik DNS, persist package caches under /drone-cache, and
keep api→shop→admin serial with single workers for the 2GiB limit.

Co-authored-by: Cursor <cursoragent@cursor.com>

.drone.yml

@@ -4,11 +4,8 @@
 #   ssh_port                      — optional, default 22
 #   deploy_path                   — absolute path on host (e.g. /opt/iled-shop)
 #
-# First-time host setup:
-#   git clone ssh://git@git.zea.lt:2222/miczek/iled-shop.git $DEPLOY_PATH
-#   cd $DEPLOY_PATH/docker && cp .env.example .env  # then edit secrets
-#
-# Pi note: steps serialize workers so builds fit under DRONE_MEMORY_LIMIT (~2GiB).
+# Homelab runner: Pi-hole DNS → Traefik LAN; /drone-cache for npm/nuget.
+# Steps stay serial + single-worker so builds fit under DRONE_MEMORY_LIMIT (~2GiB).
 
 kind: pipeline
 type: docker
@@ -18,6 +15,9 @@ platform:
   os: linux
   arch: arm64
 
+dns:
+  - 192.168.0.64
+
 clone:
   depth: 50
 
@@ -27,10 +27,15 @@ concurrency:
 steps:
   - name: api
     image: mcr.microsoft.com/dotnet/sdk:10.0
+    pull: false
     environment:
-      # One MSBuild node; disable node reuse — lower peak RAM on 4GB Pi
       DOTNET_CLI_TELEMETRY_OPTOUT: "1"
+      DOTNET_NOLOGO: "1"
       MSBUILDDISABLENODEREUSE: "1"
+      NUGET_PACKAGES: /drone-cache/nuget
+      NUGET_HTTP_CACHE_PATH: /drone-cache/nuget-http
+      DOTNET_CLI_HOME: /drone-cache/dotnet
+      NUGET_XMLDOC_MODE: skip
     commands:
       - cd src/backend
       - dotnet restore iLED.slnx
@@ -38,24 +43,28 @@ steps:
 
   - name: shop
     image: node:22-bookworm
+    pull: false
     environment:
       NG_BUILD_MAX_WORKERS: "1"
       NODE_OPTIONS: "--max-old-space-size=1536"
+      npm_config_cache: /drone-cache/npm
     commands:
       - cd src/shop
-      - npm ci
+      - npm ci --prefer-offline
       - npm run build -- --configuration=production
     depends_on:
       - api
 
   - name: admin
     image: node:22-bookworm
+    pull: false
     environment:
       NG_BUILD_MAX_WORKERS: "1"
       NODE_OPTIONS: "--max-old-space-size=1536"
+      npm_config_cache: /drone-cache/npm
     commands:
       - cd src/admin
-      - npm ci
+      - npm ci --prefer-offline
       - npm run build -- --configuration=production
     depends_on:
       - shop
@@ -75,6 +84,9 @@ platform:
   os: linux
   arch: arm64
 
+dns:
+  - 192.168.0.64
+
 depends_on:
   - ci
 
@@ -87,6 +99,7 @@ concurrency:
 steps:
   - name: ssh-deploy
     image: appleboy/drone-ssh
+    pull: false
     settings:
       host:
         from_secret: ssh_host