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/nikic/php-parser/lib/PhpParser/Node/Identifier.php

@@ -0,0 +1,85 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\Node;
+
+use PhpParser\NodeAbstract;
+
+/**
+ * Represents a non-namespaced name. Namespaced names are represented using Name nodes.
+ */
+class Identifier extends NodeAbstract {
+    /**
+     * @psalm-var non-empty-string
+     * @var string Identifier as string
+     */
+    public string $name;
+
+    /** @var array<string, bool> */
+    private static array $specialClassNames = [
+        'self'   => true,
+        'parent' => true,
+        'static' => true,
+    ];
+
+    /**
+     * Constructs an identifier node.
+     *
+     * @param string $name Identifier as string
+     * @param array<string, mixed> $attributes Additional attributes
+     */
+    public function __construct(string $name, array $attributes = []) {
+        if ($name === '') {
+            throw new \InvalidArgumentException('Identifier name cannot be empty');
+        }
+
+        $this->attributes = $attributes;
+        $this->name = $name;
+    }
+
+    public function getSubNodeNames(): array {
+        return ['name'];
+    }
+
+    /**
+     * Get identifier as string.
+     *
+     * @psalm-return non-empty-string
+     * @return string Identifier as string.
+     */
+    public function toString(): string {
+        return $this->name;
+    }
+
+    /**
+     * Get lowercased identifier as string.
+     *
+     * @psalm-return non-empty-string&lowercase-string
+     * @return string Lowercased identifier as string
+     */
+    public function toLowerString(): string {
+        return strtolower($this->name);
+    }
+
+    /**
+     * Checks whether the identifier is a special class name (self, parent or static).
+     *
+     * @return bool Whether identifier is a special class name
+     */
+    public function isSpecialClassName(): bool {
+        return isset(self::$specialClassNames[strtolower($this->name)]);
+    }
+
+    /**
+     * Get identifier as string.
+     *
+     * @psalm-return non-empty-string
+     * @return string Identifier as string
+     */
+    public function __toString(): string {
+        return $this->name;
+    }
+
+    public function getType(): string {
+        return 'Identifier';
+    }
+}