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/contracts/Tests/Cache/CacheTraitTest.php

@@ -0,0 +1,157 @@
+<?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\Contracts\Tests\Cache;
+
+use PHPUnit\Framework\TestCase;
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+use Symfony\Contracts\Cache\CacheTrait;
+
+/**
+ * @author Tobias Nyholm <tobias.nyholm@gmail.com>
+ */
+class CacheTraitTest extends TestCase
+{
+    public function testSave()
+    {
+        $item = $this->createMock(CacheItemInterface::class);
+        $item->method('set')
+            ->willReturn($item);
+        $item->method('isHit')
+            ->willReturn(false);
+
+        $item->expects($this->once())
+            ->method('set')
+            ->with('computed data');
+
+        $cache = $this->getMockBuilder(TestPool::class)
+            ->onlyMethods(['getItem', 'save'])
+            ->getMock();
+        $cache->expects($this->once())
+            ->method('getItem')
+            ->with('key')
+            ->willReturn($item);
+        $cache->expects($this->once())
+            ->method('save');
+
+        $callback = static fn (CacheItemInterface $item) => 'computed data';
+
+        $cache->get('key', $callback);
+    }
+
+    public function testNoCallbackCallOnHit()
+    {
+        $item = $this->createMock(CacheItemInterface::class);
+        $item->method('isHit')
+            ->willReturn(true);
+
+        $item->expects($this->never())
+            ->method('set');
+
+        $cache = $this->getMockBuilder(TestPool::class)
+            ->onlyMethods(['getItem', 'save'])
+            ->getMock();
+
+        $cache->expects($this->once())
+            ->method('getItem')
+            ->with('key')
+            ->willReturn($item);
+        $cache->expects($this->never())
+            ->method('save');
+
+        $callback = function (CacheItemInterface $item) {
+            $this->fail('This code should never be reached');
+        };
+
+        $cache->get('key', $callback);
+    }
+
+    public function testRecomputeOnBetaInf()
+    {
+        $item = $this->createMock(CacheItemInterface::class);
+        $item->method('set')
+            ->willReturn($item);
+        $item->method('isHit')
+            // We want to recompute even if it is a hit
+            ->willReturn(true);
+
+        $item->expects($this->once())
+            ->method('set')
+            ->with('computed data');
+
+        $cache = $this->getMockBuilder(TestPool::class)
+            ->onlyMethods(['getItem', 'save'])
+            ->getMock();
+
+        $cache->expects($this->once())
+            ->method('getItem')
+            ->with('key')
+            ->willReturn($item);
+        $cache->expects($this->once())
+            ->method('save');
+
+        $callback = static fn (CacheItemInterface $item) => 'computed data';
+
+        $cache->get('key', $callback, \INF);
+    }
+
+    public function testExceptionOnNegativeBeta()
+    {
+        $cache = new TestPool();
+
+        $callback = static fn (CacheItemInterface $item) => 'computed data';
+
+        $this->expectException(\InvalidArgumentException::class);
+        $cache->get('key', $callback, -2);
+    }
+}
+
+class TestPool implements CacheItemPoolInterface
+{
+    use CacheTrait;
+
+    public function hasItem($key): bool
+    {
+    }
+
+    public function deleteItem($key): bool
+    {
+    }
+
+    public function deleteItems(array $keys = []): bool
+    {
+    }
+
+    public function getItem($key): CacheItemInterface
+    {
+    }
+
+    public function getItems(array $key = []): iterable
+    {
+    }
+
+    public function saveDeferred(CacheItemInterface $item): bool
+    {
+    }
+
+    public function save(CacheItemInterface $item): bool
+    {
+    }
+
+    public function commit(): bool
+    {
+    }
+
+    public function clear(): bool
+    {
+    }
+}