ci: install .NET via retrying dotnet-install.sh instead of setup-dotnet

The single self-hosted act_runner intermittently fails actions/setup-dotnet:
a partial extraction sticks in the shared tool-cache (tar: Cannot open: File
exists) or the SDK tarball download corrupts. Install into a clean private
$HOME/.dotnet via dotnet-install.sh with a rm -rf + retry-once, matching the
npm ci and NuGet publish retries already in this pipeline.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitea/workflows/ci-deploy.yml

@@ -13,10 +13,22 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Setup .NET
+      - name: Setup .NET (resilient)
-        uses: actions/setup-dotnet@v4
+        shell: bash
-        with:
+        # actions/setup-dotnet on this single self-hosted runner intermittently
-          dotnet-version: '9.0.x'
+        # leaves a partial extraction in the shared tool-cache ("tar: Cannot open:
+        # File exists") or corrupts the SDK download. Install into a clean private
+        # dir via dotnet-install.sh and retry once on failure, mirroring the
+        # npm ci / NuGet retries elsewhere in this workflow.
+        run: |
+          install() {
+            curl -fsSL https://dot.net/v1/dotnet-install.sh -o /tmp/dotnet-install.sh
+            rm -rf "$HOME/.dotnet"
+            bash /tmp/dotnet-install.sh --channel 9.0 --install-dir "$HOME/.dotnet"
+          }
+          install || ( echo "dotnet install failed ($?) — retrying once..." && install )
+          echo "$HOME/.dotnet" >> "$GITHUB_PATH"
+          "$HOME/.dotnet/dotnet" --info
 
       - name: Setup Node
         uses: actions/setup-node@v4
@@ -39,7 +51,12 @@ jobs:
         run: |
           node -v
           npm -v
-          npm ci --no-audit --no-fund
+          # npm ci occasionally segfaults on the runner (SIGSEGV/139, a memory/native
+          # flake). Retry once with a clean node_modules before failing the job.
+          npm ci --no-audit --no-fund \
+            || ( echo "npm ci failed ($?) — cleaning node_modules and retrying once..." \
+                 && rm -rf node_modules \
+                 && npm ci --no-audit --no-fund )
 
       - name: Test frontend
         working-directory: job-tracker-ui

JobTrackerApi/Dockerfile

@@ -9,7 +9,14 @@ COPY Models/ Models/
 COPY JobTrackerApi/ JobTrackerApi/
 COPY JobTrackerBackend/ JobTrackerBackend/
 
-RUN dotnet publish JobTrackerApi/JobTrackerApi.csproj -c Release -o /app/publish /p:UseAppHost=false
+# Retry once after clearing NuGet caches. Transient download corruption on the
+# build host can trip NU3008 ("package integrity check failed / has changed since
+# it was signed") while restoring a transitive package; clearing the caches and
+# re-downloading resolves it.
+RUN dotnet publish JobTrackerApi/JobTrackerApi.csproj -c Release -o /app/publish /p:UseAppHost=false \
+    || ( echo "Publish failed — clearing NuGet caches and retrying once..." \
+         && dotnet nuget locals all --clear \
+         && dotnet publish JobTrackerApi/JobTrackerApi.csproj -c Release -o /app/publish /p:UseAppHost=false )
 
 FROM mcr.microsoft.com/dotnet/aspnet:9.0 AS runtime