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/Builder/Function_.php

@@ -0,0 +1,67 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\Builder;
+
+use PhpParser;
+use PhpParser\BuilderHelpers;
+use PhpParser\Node;
+use PhpParser\Node\Stmt;
+
+class Function_ extends FunctionLike {
+    protected string $name;
+    /** @var list<Stmt> */
+    protected array $stmts = [];
+
+    /** @var list<Node\AttributeGroup> */
+    protected array $attributeGroups = [];
+
+    /**
+     * Creates a function builder.
+     *
+     * @param string $name Name of the function
+     */
+    public function __construct(string $name) {
+        $this->name = $name;
+    }
+
+    /**
+     * Adds a statement.
+     *
+     * @param Node|PhpParser\Builder $stmt The statement to add
+     *
+     * @return $this The builder instance (for fluid interface)
+     */
+    public function addStmt($stmt) {
+        $this->stmts[] = BuilderHelpers::normalizeStmt($stmt);
+
+        return $this;
+    }
+
+    /**
+     * Adds an attribute group.
+     *
+     * @param Node\Attribute|Node\AttributeGroup $attribute
+     *
+     * @return $this The builder instance (for fluid interface)
+     */
+    public function addAttribute($attribute) {
+        $this->attributeGroups[] = BuilderHelpers::normalizeAttribute($attribute);
+
+        return $this;
+    }
+
+    /**
+     * Returns the built function node.
+     *
+     * @return Stmt\Function_ The built function node
+     */
+    public function getNode(): Node {
+        return new Stmt\Function_($this->name, [
+            'byRef'      => $this->returnByRef,
+            'params'     => $this->params,
+            'returnType' => $this->returnType,
+            'stmts'      => $this->stmts,
+            'attrGroups' => $this->attributeGroups,
+        ], $this->attributes);
+    }
+}