refactor: Cleanup git state - commit all staged changes

Major refactoring cleanup:
- Add new controller architecture (class-controller-*.php)
- Add new settings-v2 UI (views/settings-v2/)
- Add new CSS architecture (agentic-sidebar.css, tokens)
- Add esbuild build pipeline (scripts/build.js, package.json)
- Add composer dependencies (vendor/)
- Add frontend src directory (assets/js/src/index.jsx)
- Add documentation files
- Remove old/obsolete files (class-settings.php, old CSS)

This commits all pending changes from previous refactoring efforts.

vendor/squizlabs/php_codesniffer/tests/EndToEnd/phpcs_test.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+function test_phpcs_is_working() {
+  assert_successful_code "$(bin/phpcs --no-cache --standard=tests/EndToEnd/Fixtures/endtoend.xml.dist tests/EndToEnd/Fixtures/ClassOneWithoutStyleError.inc tests/EndToEnd/Fixtures/ClassTwoWithoutStyleError.inc)"
+}
+
+function test_phpcs_is_working_in_parallel() {
+  assert_successful_code "$(bin/phpcs --no-cache --parallel=2 --standard=tests/EndToEnd/Fixtures/endtoend.xml.dist tests/EndToEnd/Fixtures/ClassOneWithoutStyleError.inc tests/EndToEnd/Fixtures/ClassTwoWithoutStyleError.inc)"
+}
+
+function test_phpcs_returns_error_on_issues() {
+  OUTPUT="$(bin/phpcs --no-colors --no-cache --standard=tests/EndToEnd/Fixtures/endtoend.xml.dist tests/EndToEnd/Fixtures/ClassWithStyleError.inc)"
+  assert_exit_code 2
+
+  assert_contains "E 1 / 1 (100%)" "$OUTPUT"
+  assert_contains "FOUND 1 ERROR AFFECTING 1 LINE" "$OUTPUT"
+}
+
+function test_phpcs_bug_1112() {
+  # See https://github.com/PHPCSStandards/PHP_CodeSniffer/issues/1112
+    if [[ "$(uname)" == "Darwin" ]]; then
+      # Perform some magic with `& fg` to prevent the processes from turning into a background job.
+      assert_successful_code "$(bash -ic 'bash --init-file <(echo "echo \"Subprocess\"") -c "bin/phpcs --no-cache --parallel=2 --standard=tests/EndToEnd/Fixtures/endtoend.xml.dist tests/EndToEnd/Fixtures/ClassOneWithoutStyleError.inc tests/EndToEnd/Fixtures/ClassTwoWithoutStyleError.inc" & fg')"
+    else
+      # This is not needed on Linux / GitHub Actions
+      assert_successful_code "$(bash -ic 'bash --init-file <(echo "echo \"Subprocess\"") -c "bin/phpcs --no-cache --parallel=2 --standard=tests/EndToEnd/Fixtures/endtoend.xml.dist tests/EndToEnd/Fixtures/ClassOneWithoutStyleError.inc tests/EndToEnd/Fixtures/ClassTwoWithoutStyleError.inc"')"
+    fi
+}