feat: setup monorepo using pnpm (#20)

* tests: fix float problems and PAT problem

* extend CONTRIBUTING.md

* extend build documentation, add GH action, fix build on MacOS

* fix build on Vercel

* update .gitignore and CONTRIBUTING.md

* feat: begin work on monorepo

* chore(actions/basic-build): use pnpm

* fix: vercel-deploy

* docs: updates with new folders

* chore: apply PR review comments

---------

Co-authored-by: martin-mfg <2026226+martin-mfg@users.noreply.github.com>

apps/backend/.github/workflows/codeql-analysis.yml

@@ -0,0 +1,43 @@
+name: "Static code analysis workflow (CodeQL)"
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+permissions:
+  actions: read
+  checks: read
+  contents: read
+  deployments: read
+  issues: read
+  discussions: read
+  packages: read
+  pages: read
+  pull-requests: read
+  repository-projects: read
+  security-events: write
+  statuses: read
+
+jobs:
+  CodeQL-Build:
+    if: github.repository == 'anuraghazra/github-readme-stats'
+
+    # CodeQL runs on ubuntu-latest, windows-latest, and macos-latest
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+
+      # Initializes the CodeQL tools for scanning.
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@46a6823b81f2d7c67ddf123851eea88365bc8a67 # v2.13.5
+        with:
+          languages: javascript
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@46a6823b81f2d7c67ddf123851eea88365bc8a67 # v2.13.5