fix: update discourse-mcp to use Node.js 24 alpine image

- Changed from build context to using node:24-alpine image directly
- Updated discourse-mcp Dockerfile to node:24-alpine
- Changed npm ci to npm install in Dockerfile
- Added note about npx usage due to TypeScript compilation errors in 0.2.4

dockerfiles/discourse-mcp/Dockerfile

@@ -1,10 +1,10 @@
-FROM node:22-alpine
+FROM node:24-alpine
 
 WORKDIR /app
 
-COPY package.json package-lock.json* ./
+COPY package.json ./
 
-RUN npm ci
+RUN npm install
 
 COPY . .