Fix pr.yaml: restore 3.1.x SDK to Linux/Windows setup-dotnet, remove duplicates

.gitattributes

@@ -0,0 +1,51 @@
+# Auto detect text files and perform LF normalization
+* text=auto eol=lf
+
+# Source code
+*.cs text eol=lf
+*.csx text eol=lf
+*.vb text eol=lf
+*.fs text eol=lf
+*.fsx text eol=lf
+
+# Scripts
+# PowerShell scripts: CRLF line endings (intentional override)
+# Both .gitattributes and .editorconfig consistently configure PowerShell files
+# to use CRLF (Windows-style) line endings for PowerShell convention compliance.
+# See .editorconfig [*.ps1] section for the matching configuration.
+*.ps1 text eol=crlf
+
+
+# Build and configuration files
+*.xml text eol=lf
+*.csproj text eol=lf
+*.vbproj text eol=lf
+*.fsproj text eol=lf
+*.sln text eol=lf
+*.slnx text eol=lf
+*.props text eol=lf
+*.targets text eol=lf
+*.ruleset text eol=lf
+*.config text eol=lf
+*.json text eol=lf
+*.yml text eol=lf
+*.yaml text eol=lf
+
+# Documentation
+*.md text eol=lf
+*.txt text eol=lf
+
+# SVG files (XML-based text)
+*.svg text eol=lf
+
+# Denote all files that are truly binary and should not be modified
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.pdf binary
+*.dll binary
+*.exe binary
+*.nupkg binary
+*.snupkg binary

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -0,0 +1,50 @@
+name: "🚀 Feature request"
+description: "💡 Suggest an idea for this project"
+title: "[Feature] <title>"
+labels: [enhancement, feature-request]
+assignees: []
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## Thanks for suggesting a feature!
+
+        Please use this form to propose a new feature or enhancement for this project. Providing as much detail as possible helps us understand your idea and evaluate it effectively.
+
+        When completing this form, please:
+        - Describe the problem this feature will address.
+        - Explain the solution you'd like to see.
+        - List any alternative approaches you've considered.
+        - Add any relevant context, examples, or screenshots.
+  - type: textarea
+    id: problem
+    attributes:
+      label: Is your feature request related to a problem? Please describe.
+      description: A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+      placeholder: Please describe the problem this feature will solve.
+    validations:
+      required: true
+  - type: textarea
+    id: solution
+    attributes:
+      label: Describe the solution you'd like
+      description: A clear and concise description of what you want to happen.
+      placeholder: What do you want to happen?
+    validations:
+      required: true
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Describe alternatives you've considered
+      description: A clear and concise description of any alternative solutions or features you've considered.
+      placeholder: List any alternative solutions or features you've tried or considered.
+    validations:
+      required: false
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional context
+      description: Add any other context or screenshots about the feature request here.
+      placeholder: Any other context to explain your request?
+    validations:
+      required: false

.github/copilot-instructions.md

@@ -0,0 +1,3 @@
+# Copilot Coding Agent Instructions
+
+## Repository Summary

.github/dependabot.yml

@@ -1,46 +1,14 @@
 version: 2
 updates:
   - package-ecosystem: "nuget"
-    directory: "/" # Root - for solution-level dependencies
+    directory: "/"
     schedule:
       interval: "weekly"
-    open-pull-requests-limit: 5
-    labels:
-      - "dependencies"
-      - "dotnet"
-
-  - package-ecosystem: "nuget"
-    directory: "/src"
-    schedule:
-      interval: "weekly"
-    open-pull-requests-limit: 5
-    labels:
-      - "dependencies"
-      - "dotnet"
-
-  - package-ecosystem: "nuget"
-    directory: "/tests"
-    schedule:
-      interval: "weekly"
-    open-pull-requests-limit: 5
-    labels:
-      - "dependencies"
-      - "dotnet"
-
-  - package-ecosystem: "nuget"
-    directory: "/benchmarks"
-    schedule:
-      interval: "weekly"
-    open-pull-requests-limit: 5
-    labels:
-      - "dependencies"
-      - "dotnet"
-
-  - package-ecosystem: "nuget"
-    directory: "/examples"
-    schedule:
-      interval: "weekly"
-    open-pull-requests-limit: 5
+    open-pull-requests-limit: 10
     labels:
       - "dependencies"
       - "dotnet"
+    groups:
+      dotnet-dependencies:
+        patterns:
+          - "*"

.github/version-picker-template.html

@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>{{TITLE}}</title>
+  <style>
+    body {
+      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
+      background: #1e1e2e;
+      color: #cdd6f4;
+      display: flex;
+      flex-direction: column;
+      align-items: center;
+      padding: 3rem 1rem;
+      min-height: 100vh;
+      margin: 0;
+    }
+    h1 { font-size: 2rem; margin-bottom: 0.5rem; color: #cba6f7; }
+    p  { color: #a6adc8; margin-bottom: 2rem; }
+    ul { list-style: none; padding: 0; width: 100%; max-width: 480px; }
+    li a {
+      display: block; padding: 0.75rem 1.25rem; margin-bottom: 0.5rem;
+      border-radius: 6px; background: #313244; color: #89b4fa;
+      text-decoration: none; font-size: 1.05rem; transition: background 0.15s;
+    }
+    li a:hover { background: #45475a; }
+    li.latest a { background: #1e66f5; color: #fff; font-weight: bold; }
+    li.latest a:hover { background: #1959d9; }
+  </style>
+</head>
+<body>
+  <h1>{{TITLE}}</h1>
+  <p>Select a documentation version:</p>
+  <ul>
+{{VERSION_LIST}}
+  </ul>
+</body>
+</html>