Standardize CI matrix policy and doc workflow

Category A: macos-26 + Swift 6.2. Add Linux CI (swift:6.2 container).
Add workflow_dispatch to doc workflow.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: RISCfuture

.github/workflows/ci.yml

@@ -1,3 +1,13 @@
+# CI Matrix Policy
+#
+# Category A (tools-version 6.2 + macOS 26 min): macos-26 + Swift 6.2
+# Category B (tools-version 6.2 + older macOS):  macos-15 + 6.2, macos-26 + 6.2
+# Category C (tools-version 6.0):                macos-15 + 6.0, macos-15 + 6.2, macos-26 + 6.2
+# Linux (if viable):                             ubuntu + Swift 6.0, ubuntu + Swift 6.2
+#
+# When Swift 6.3 ships: bump 6.0→6.1 and 6.2→6.3 in Category C
+# When bumping tools-version to 6.2: drop 6.0/6.1, move to Category A or B
+
 name: CI
 
 on:
@@ -29,6 +39,17 @@ jobs:
         run: swift build -v
       - name: Test
         run: swift test -v
+  test-linux:
+    name: Test on Linux
+    runs-on: ubuntu-latest
+    container:
+      image: swift:6.2
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build
+        run: swift build -v
+      - name: Test
+        run: swift test -v
   lint:
     name: Run Swiftlint
     runs-on: ubuntu-latest

.github/workflows/doc.yml

@@ -1,23 +1,20 @@
-# Sample workflow for building and deploying a Jekyll site to GitHub Pages
 name: Deploy Documentation
 
 on:
   push:
     branches: [main]
+  workflow_dispatch:
 
-# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
 permissions:
   contents: read
   pages: write
   id-token: write
 
-# Allow one concurrent deployment
 concurrency:
   group: pages
   cancel-in-progress: true
 
 jobs:
-  # Build job
   build:
     name: Generate Documentation
     runs-on: macos-latest
@@ -57,7 +54,6 @@ jobs:
         with:
           path: "docs/"
 
-  # Deployment job
   deploy:
     environment:
       name: github-pages