Use next patch version when using main action script

Updated the version resolution logic to prefer workflow input and increment the patch version correctly.

This will prevent auto downgrading from stable repository.

action.yml

@@ -140,9 +140,33 @@ runs:
     - shell: bash
       run: |
 
-        # read version from upstream Armbian OS
-        cat os/stable.json | jq '.version' | sed "s/\"//g" | sed 's/^/ARMBIAN_VERSION=/' >> $GITHUB_ENV
-        [[ "${{ inputs.armbian_version }}" != '' ]] && echo "ARMBIAN_VERSION=${{ inputs.armbian_version }}" >> $GITHUB_ENV
+        # Resolve base version (prefer workflow input if provided)
+        BASE_VERSION="${{ inputs.armbian_version }}"
+        if [ -z "$BASE_VERSION" ]; then
+          BASE_VERSION="$(jq -r '.version' os/stable.json)"
+        fi
+
+        # Preserve optional 'v' prefix but strip it for math
+        PREFIX=''
+        if [[ "$BASE_VERSION" == v* ]]; then
+          PREFIX='v'
+          BASE_NO_PREFIX="${BASE_VERSION#v}"
+        else
+          BASE_NO_PREFIX="$BASE_VERSION"
+        fi
+
+        # Drop any pre-release/build metadata (e.g., -rc1, +meta)
+        CORE="${BASE_NO_PREFIX%%[-+]*}"
+
+        # Split and increment patch
+        IFS='.' read -r MAJOR MINOR PATCH <<<"$CORE"
+        PATCH=${PATCH:-0}
+        NEXT_PATCH=$((PATCH + 1))
+        NEXT_VERSION="${PREFIX}${MAJOR}.${MINOR}.${NEXT_PATCH}"
+
+        {
+          echo "ARMBIAN_VERSION=${NEXT_VERSION}"
+        } >> "$GITHUB_ENV"
 
         # copy os userpatches and custom
         mkdir -pv build/userpatches