Add workflows for linting and syncing subtrees, and update subtrees.json format

examples/c/.github/subtrees.json

@@ -0,0 +1 @@
+[]

examples/c/.github/workflows/lint-subtrees.yml

@@ -0,0 +1,19 @@
+name: Lint subtrees.json
+
+on:
+  pull_request:
+    paths:
+      - '.github/subtrees.json'
+  workflow_call:
+  workflow_dispatch:
+
+jobs:
+  lint-subtrees:
+    runs-on: ubuntu-latest
+    env:
+      CI_SERVER_HOST: github.com
+      GROUP: usgs-coupled
+    steps:
+      - uses: usgs-coupled/sync-subtrees-action/lint-subtrees/@main
+        with:
+          ssh-private-key: ${{ secrets.SSH_PRIVATE_KEY }}

examples/c/.github/workflows/subtree.yml

@@ -0,0 +1,33 @@
+name: Sync Subtrees
+
+on:
+  workflow_dispatch:
+    inputs:
+      dryRun:
+        description: 'If true, don’t push any changes (for testing only).'
+        required: true
+        default: true
+        type: boolean
+      testMerge:
+        description: 'Run in test mode, pushing to a test branch.'
+        required: true
+        default: false
+        type: boolean
+
+jobs:
+  sync-subtrees:
+    runs-on: ubuntu-latest
+    env:
+      CI_SERVER_HOST: github.com
+      GROUP: usgs-coupled
+      GH_TOKEN: ${{ secrets.WORKFLOW_PAT }}
+    steps:
+      - name: Run sync-subtrees-action
+        uses: usgs-coupled/sync-subtrees-action@main
+        with:
+          dryRun: ${{ inputs.dryRun }}
+          testMerge: ${{ inputs.testMerge }}
+          repository_name: ${{ github.event.repository.name }}
+          default_branch: ${{ github.event.repository.default_branch }}
+          run_number: ${{ github.run_number }}
+          ssh_private_key: ${{ secrets.SSH_PRIVATE_KEY }}

src/phreeqcpp/.github/subtrees.json

@@ -1,6 +1,7 @@
 [
   {
     "prefix": "common",
-    "url": "git@${CI_SERVER_HOST}:${GROUP}-subtrees/phreeqc3-src-common.git"
+    "url": "git@${CI_SERVER_HOST}:${GROUP}-subtrees/phreeqc3-src-common.git",
+    "repo": "usgs-coupled-subtrees/phreeqc3-src-common"
   }
 ]