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/symfony/dependency-injection/ParameterBag/ContainerBagInterface.php

@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\DependencyInjection\ParameterBag;
+
+use Psr\Container\ContainerInterface;
+use Symfony\Component\DependencyInjection\Exception\ParameterNotFoundException;
+
+/**
+ * ContainerBagInterface is the interface implemented by objects that manage service container parameters.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+interface ContainerBagInterface extends ContainerInterface
+{
+    /**
+     * Gets the service container parameters.
+     */
+    public function all(): array;
+
+    /**
+     * Replaces parameter placeholders (%name%) by their values.
+     *
+     * @template TValue of array<array|scalar>|scalar
+     *
+     * @param TValue $value
+     *
+     * @return mixed
+     *
+     * @psalm-return (TValue is scalar ? array|scalar : array<array|scalar>)
+     *
+     * @throws ParameterNotFoundException if a placeholder references a parameter that does not exist
+     */
+    public function resolveValue(mixed $value);
+
+    /**
+     * Escape parameter placeholders %.
+     */
+    public function escapeValue(mixed $value): mixed;
+
+    /**
+     * Unescape parameter placeholders %.
+     */
+    public function unescapeValue(mixed $value): mixed;
+}