ci: fix source-check checkout and manifest guards

.gitea/workflows/cicd-source-checks.yaml

@@ -171,18 +171,25 @@ jobs:
 
           if GIT_SSH_COMMAND="ssh -i ~/.ssh/id_rsa -o IdentitiesOnly=yes -o StrictHostKeyChecking=no" \
             git fetch --depth 1 origin "${HEAD_SHA}" >/dev/null 2>&1; then
-            git checkout FETCH_HEAD -- backend
+            git checkout FETCH_HEAD -- .
             echo "Using fetched HEAD_SHA checkout: ${HEAD_SHA}"
           else
-            git checkout HEAD -- backend
+            git checkout HEAD -- .
             echo "Falling back to default branch HEAD for backend source checkout"
           fi
 
+          test -f backend/pyproject.toml || {
+            echo "❌ Missing backend/pyproject.toml after checkout"
+            find . -maxdepth 3 -type f | sort | head -n 80
+            exit 1
+          }
+
       - name: Run backend format/lint/type checks
         run: |
           set -e
           docker run --rm -v "$PWD:/workspace" -w /workspace/backend python:3.14-slim bash -lc '
             set -e
+            test -f pyproject.toml
             python -m pip install --disable-pip-version-check --no-cache-dir uv
             uv sync --dev
             uv run ruff format --check .
@@ -235,18 +242,25 @@ jobs:
 
           if GIT_SSH_COMMAND="ssh -i ~/.ssh/id_rsa -o IdentitiesOnly=yes -o StrictHostKeyChecking=no" \
             git fetch --depth 1 origin "${HEAD_SHA}" >/dev/null 2>&1; then
-            git checkout FETCH_HEAD -- frontend
+            git checkout FETCH_HEAD -- .
             echo "Using fetched HEAD_SHA checkout: ${HEAD_SHA}"
           else
-            git checkout HEAD -- frontend
+            git checkout HEAD -- .
             echo "Falling back to default branch HEAD for frontend source checkout"
           fi
 
+          test -f frontend/package.json || {
+            echo "❌ Missing frontend/package.json after checkout"
+            find . -maxdepth 3 -type f | sort | head -n 80
+            exit 1
+          }
+
       - name: Run frontend format/lint/type checks
         run: |
           set -e
           docker run --rm -v "$PWD:/workspace" -w /workspace/frontend node:24-bullseye bash -lc '
             set -e
+            test -f package.json
             corepack enable
             yarn install --immutable || yarn install
             yarn prettier --check src/