Add run-formatters.sh script and update GitHub workflow

This commit adds a new bin/run-formatters.sh script that can both check and fix code formatting.
The script handles Go code formatting with gofumpt and webui formatting with Prettier.
The GitHub workflow has been updated to use this script in check mode.

Co-Authored-By: sketch <hello@sketch.dev>
diff --git a/.github/workflows/formatting.yml b/.github/workflows/formatting.yml
index 69d8721..61c5d75 100644
--- a/.github/workflows/formatting.yml
+++ b/.github/workflows/formatting.yml
@@ -24,10 +24,6 @@
         working-directory: ./webui
         run: npm ci
 
-      - name: Check Prettier formatting
-        working-directory: ./webui
-        run: npx prettier --check .
-
       # Setup for gofumpt
       - name: Setup Go
         uses: actions/setup-go@v4
@@ -40,5 +36,5 @@
           go install mvdan.cc/gofumpt@v0.8.0
           echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
 
-      - name: Check Go formatting
-        run: gofumpt -l . | grep . && { echo "Go files need formatting"; exit 1; } || echo "Go formatting check passed"
+      - name: Check formatting
+        run: bin/run-formatters.sh check