Add LICENSE year validation for new bridge files

Validate that newly added LICENSE files have the correct first line
format: "Copyright (c) {YEAR}-present Fabien Potencier" where YEAR
is the current year. Existing and modified LICENSE files are not
affected by this check.

Also update the workflow to fetch the base branch so the script can
properly detect which LICENSE files are new.

.github/scripts/validate-bridge-files.sh

@@ -36,6 +36,7 @@ REQUIRED_FILES=(
 )
 
 ERRORS=0
+CURRENT_YEAR=$(date +%Y)
 
 echo "Validating ${BRIDGE_TYPE} bridges have required files (${BRIDGE_PATH})..."
 echo ""
@@ -57,16 +58,39 @@ for bridge_dir in ${BRIDGE_PATH}/; do
         fi
     done
 
+    # Check newly added LICENSE files have correct first line
+    license_file="${bridge_dir}LICENSE"
+    if [[ -f "$license_file" ]]; then
+        # Determine base ref for comparison (PR base branch or default branch)
+        if [[ -n "${GITHUB_BASE_REF:-}" ]]; then
+            BASE_REF="origin/${GITHUB_BASE_REF}"
+        else
+            BASE_REF="origin/main"
+        fi
+
+        # Check if LICENSE file is newly added (not in base branch)
+        # Use git show which works with shallow clones if base is fetched
+        if ! git show "${BASE_REF}:${license_file}" &>/dev/null; then
+            expected_first_line="Copyright (c) ${CURRENT_YEAR}-present Fabien Potencier"
+            actual_first_line=$(head -n 1 "$license_file")
+            if [[ "$actual_first_line" != "$expected_first_line" ]]; then
+                echo "::error file=${license_file}::${BRIDGE_TYPE} bridge '$bridge_name' LICENSE file first line must be '${expected_first_line}'"
+                bridge_errors=$((bridge_errors + 1))
+                ERRORS=$((ERRORS + 1))
+            fi
+        fi
+    fi
+
     if [[ $bridge_errors -eq 0 ]]; then
-        echo "✓ $bridge_name: all required files present"
+        echo "✓ $bridge_name: all required files present and valid"
     fi
 done
 
 if [[ $ERRORS -gt 0 ]]; then
     echo ""
-    echo "::error::Found $ERRORS missing required file(s) in ${BRIDGE_TYPE} bridges"
+    echo "::error::Found $ERRORS validation error(s) in ${BRIDGE_TYPE} bridges"
     exit 1
 fi
 
 echo ""
-echo "All ${BRIDGE_TYPE} bridges have required files!"
+echo "All ${BRIDGE_TYPE} bridges have required files and valid content!"

.github/workflows/validation.yaml

@@ -34,6 +34,9 @@ jobs:
             - name: Checkout
               uses: actions/checkout@v6
 
+            - name: Fetch base branch for LICENSE validation
+              run: git fetch origin ${{ github.base_ref || 'main' }} --depth=1
+
             - name: Validate store bridge naming conventions
               run: .github/scripts/validate-bridge-naming.sh store store src/ai-bundle/config/options.php
 
@@ -53,6 +56,9 @@ jobs:
             - name: Checkout
               uses: actions/checkout@v6
 
+            - name: Fetch base branch for LICENSE validation
+              run: git fetch origin ${{ github.base_ref || 'main' }} --depth=1
+
             - name: Validate tool bridge naming conventions
               run: .github/scripts/validate-bridge-naming.sh tool agent
 
@@ -72,6 +78,9 @@ jobs:
             - name: Checkout
               uses: actions/checkout@v6
 
+            - name: Fetch base branch for LICENSE validation
+              run: git fetch origin ${{ github.base_ref || 'main' }} --depth=1
+
             - name: Validate message store bridge naming conventions
               run: .github/scripts/validate-bridge-naming.sh message-store chat
 
@@ -91,6 +100,9 @@ jobs:
             - name: Checkout
               uses: actions/checkout@v6
 
+            - name: Fetch base branch for LICENSE validation
+              run: git fetch origin ${{ github.base_ref || 'main' }} --depth=1
+
             - name: Validate platform bridge naming conventions
               run: .github/scripts/validate-bridge-naming.sh platform platform
 
@@ -110,6 +122,9 @@ jobs:
             - name: Checkout
               uses: actions/checkout@v6
 
+            - name: Fetch base branch for LICENSE validation
+              run: git fetch origin ${{ github.base_ref || 'main' }} --depth=1
+
             - name: Validate Mate bridge naming conventions
               run: .github/scripts/validate-bridge-naming.sh mate-extension mate