chore(sfu): move from npm to yarn (#35)

Author: BreadGenie

.github/copilot-instructions.md

@@ -824,8 +824,8 @@ function cleanupParticipant(socketId: string, meetingId: string) {
 
 ### Running the Server
 
-- Development: `npm run dev` or `npm run dev:watch` (with nodemon)
-- Production: `npm run build && npm start`
+- Development: `yarn dev` or `yarn dev:watch` (with nodemon)
+- Production: `yarn build && yarn start`
 - Assume SFU server is already running during development
 
 ### Logging
@@ -856,8 +856,8 @@ function cleanupParticipant(socketId: string, meetingId: string) {
 ## Code Quality
 
 - Use Biome for linting and formatting (both frontend and SFU server)
-- Run `yarn lint` or `npm run lint` to check code
-- Run `yarn format` or `npm run format` to fix formatting
+- Run `yarn lint` to check code
+- Run `yarn format` to fix formatting
 - Ignore newline errors in all files
 - Write clean, readable code that follows project conventions
 

.github/workflows/linter.yml

@@ -26,11 +26,11 @@ jobs:
       - uses: actions/setup-node@v4
         with:
           node-version: 24
-          cache: "npm"
-          cache-dependency-path: "**/package-lock.json"
+          cache: "yarn"
+          cache-dependency-path: "**/yarn.lock"
 
       - name: Install SFU Server dependencies
-        run: cd sfu-server && npm ci
+        run: cd sfu-server && yarn install --frozen-lockfile
 
       - uses: pre-commit/action@v3.0.0
 

.pre-commit-config.yaml

@@ -52,7 +52,7 @@ repos:
 
       - id: biome-check
         name: Biome Check (SFU Server)
-        entry: bash -c 'cd sfu-server && npm run lint:fix'
+        entry: bash -c 'cd sfu-server && yarn lint:fix'
         language: system
         files: "sfu-server/.*\\.(js|ts|json)$"
         exclude: |

sfu-server/Dockerfile

@@ -13,10 +13,12 @@ COPY types /app/types
 
 # Copy sfu-server source code
 WORKDIR /app/sfu-server
-COPY sfu-server/package*.json sfu-server/tsconfig.json ./
-RUN npm ci
+COPY sfu-server/package.json sfu-server/yarn.lock sfu-server/tsconfig.json ./
+RUN corepack enable
+RUN corepack prepare yarn@1.22.22 --activate
+RUN yarn install --frozen-lockfile
 COPY sfu-server/src ./src
-RUN npm run build
+RUN yarn build
 
 # --- Runtime stage (minimal) ---
 FROM node:${NODE_VERSION} AS runtime