Rename CI workflow to "Build / Test" and update docs

Renamed the workflow in ci.yml from "CI" to "Build / Test" for clarity. Updated all references in README.md, including the branch protection section, and added a status badge for the new workflow name. Clarified branch protection instructions to match the updated workflow.

Author: kzdev-net

.github/workflows/ci.yml

@@ -1,4 +1,4 @@
-name: CI
+name: Build / Test
 
 on:
   push:

README.md

@@ -1,5 +1,7 @@
 # KZDev.PerfUtils
 
+[![Build / Test](https://github.com/kzdev-net/kzdev.perfutils/actions/workflows/ci.yml/badge.svg)](https://github.com/kzdev-net/kzdev.perfutils/actions/workflows/ci.yml)
+
 This repository contains the  ['KZDev.PerfUtils'](https://www.nuget.org/packages/KZDev.PerfUtils) NuGet package, which provides the following high-performance utilities:
 
 - **MemoryStreamSlim**: A memory-efficient, high-performance stream for large or frequently resized in-memory buffers, modeled on **MemoryStream** with a largely compatible API.

Source/Tst/README.md

@@ -63,11 +63,11 @@ Add **`[Trait(TestConstants.TestTrait.TestMode, TestConstants.TestMode.Explicit)
 
 ---
 
-## Maintainers: branch protection (CI)
+## Maintainers: branch protection (Build / Test)
 
-Configure GitHub **branch protection** status checks to match how CI gates merges:
+Configure GitHub **branch protection** status checks to match how the workflow gates merges:
 
-- **`main`:** Require **`test-standard`** and **`test-explicit`** from the **CI** workflow so both jobs must pass before merge.
+- **`main`:** Require **`test-standard`** and **`test-explicit`** from the **Build / Test** workflow so both jobs must pass before merge.
 - **`dev`:** Require **`test-standard`** only. **`test-explicit`** is informational on `dev` (workflow uses `continue-on-error` for pushes to `dev` and for pull requests whose base branch is not `main`).
 
 Fork pull requests need repository settings that allow GitHub Actions to run from forks if you want CI for external contributors.