chore: skip .NET steps on PR when server paths unchanged

.github/workflows/dotnet.yml

@@ -1,6 +1,8 @@
 # Build and test the C# solution (server + tests). Targets repo root NeonSprawl.sln.
-# pull_request has no paths filter so this job always runs on PRs to main — add check
+# PRs: workflow always runs (so ".NET / build" can be a required check). Path-sensitive
-# ".NET / build" under branch protection required status checks (see PR gate workflow comment).
+# work uses step-level `if` — skipped steps still leave the job successful (unlike a
+# workflow skipped via `on.paths`, which leaves the required check missing/pending).
+# push: path filter on `on` avoids redundant runs on unrelated commits to main.
 name: .NET
 
 on:
@@ -34,18 +36,37 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Detect .NET-relevant changes (PR only)
+        id: paths
+        if: github.event_name == 'pull_request'
+        uses: dorny/paths-filter@v3
+        with:
+          filters: |
+            server:
+              - "NeonSprawl.sln"
+              - "server/**"
+              - ".github/workflows/dotnet.yml"
+
+      - name: Skip .NET build (no server-side paths in this PR)
+        if: github.event_name == 'pull_request' && steps.paths.outputs.server != 'true'
+        run: echo "Skipping .NET restore, build, and tests."
+
       - name: Setup .NET
+        if: github.event_name == 'push' || steps.paths.outputs.server == 'true'
         uses: actions/setup-dotnet@v4
         with:
           dotnet-version: 10.0.x
 
       - name: Restore
+        if: github.event_name == 'push' || steps.paths.outputs.server == 'true'
         run: dotnet restore NeonSprawl.sln
 
       - name: Build
+        if: github.event_name == 'push' || steps.paths.outputs.server == 'true'
         run: dotnet build NeonSprawl.sln --no-restore --configuration Release
 
       - name: Test
+        if: github.event_name == 'push' || steps.paths.outputs.server == 'true'
         env:
           ConnectionStrings__NeonSprawl: >-
             Host=localhost;Port=5432;Database=neon_sprawl;Username=neon_sprawl;Password=neon_sprawl_dev