chore: stop tracking .gsd planning tooling

Per project rule that tooling (claude, gsd, etc.) should not live in the
repo. Local files are untouched; .gsd/ is now gitignored.

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

.gitea/workflows/ci-deploy.yml

@@ -13,22 +13,10 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Setup .NET (resilient)
-        shell: bash
-        # actions/setup-dotnet on this single self-hosted runner intermittently
-        # 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 .NET
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '9.0.x'
 
       - name: Setup Node
         uses: actions/setup-node@v4