refactor(i18n): use JSON with flattened key and namespace (#30114)

Co-authored-by: yyh <yuanyouhuilyz@gmail.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

.github/workflows/translate-i18n-base-on-english.yml

@@ -4,7 +4,7 @@ on:
   push:
     branches: [main]
     paths:
-      - 'web/i18n/en-US/*.ts'
+      - 'web/i18n/en-US/*.json'
 
 permissions:
   contents: write
@@ -28,13 +28,13 @@ jobs:
         run: |
           git fetch origin "${{ github.event.before }}" || true
           git fetch origin "${{ github.sha }}" || true
-          changed_files=$(git diff --name-only "${{ github.event.before }}" "${{ github.sha }}" -- 'i18n/en-US/*.ts')
+          changed_files=$(git diff --name-only "${{ github.event.before }}" "${{ github.sha }}" -- 'i18n/en-US/*.json')
           echo "Changed files: $changed_files"
           if [ -n "$changed_files" ]; then
             echo "FILES_CHANGED=true" >> $GITHUB_ENV
             file_args=""
             for file in $changed_files; do
-              filename=$(basename "$file" .ts)
+              filename=$(basename "$file" .json)
               file_args="$file_args --file $filename"
             done
             echo "FILE_ARGS=$file_args" >> $GITHUB_ENV