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/psr/http-message/composer.json

@@ -0,0 +1,26 @@
+{
+    "name": "psr/http-message",
+    "description": "Common interface for HTTP messages",
+    "keywords": ["psr", "psr-7", "http", "http-message", "request", "response"],
+    "homepage": "https://github.com/php-fig/http-message",
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "PHP-FIG",
+            "homepage": "https://www.php-fig.org/"
+        }
+    ],
+    "require": {
+        "php": "^7.2 || ^8.0"
+    },
+    "autoload": {
+        "psr-4": {
+            "Psr\\Http\\Message\\": "src/"
+        }
+    },
+    "extra": {
+        "branch-alias": {
+            "dev-master": "2.0.x-dev"
+        }
+    }
+}