Add PocketBase client with contracts and sharp build tooling

Directory.Build.props

@@ -0,0 +1,20 @@
+<Project>
+
+    <!-- Solution-wide build settings, applied to every project. Package versions
+         live in Directory.Packages.props; this file carries code-quality settings. -->
+    <PropertyGroup>
+        <!-- Turn on the full set of built-in .NET analyzers (code quality + style),
+             including the opt-in rules. -->
+        <EnableNETAnalyzers>true</EnableNETAnalyzers>
+        <AnalysisMode>All</AnalysisMode>
+        <AnalysisLevel>latest-all</AnalysisLevel>
+
+        <!-- Enforce .editorconfig code-style rules as part of the build, not just
+             in the IDE. -->
+        <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
+
+        <!-- Any warning fails the build, so quality issues cannot be ignored. -->
+        <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    </PropertyGroup>
+
+</Project>