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/sebastian/code-unit/.psalm/baseline.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<files psalm-version="4.0.1@b1e2e30026936ef8d5bf6a354d1c3959b6231f44">
+  <file src="src/Mapper.php">
+    <ArgumentTypeCoercion occurrences="16">
+      <code>$firstPart</code>
+      <code>$firstPart</code>
+      <code>$firstPart</code>
+      <code>$firstPart</code>
+      <code>$firstPart</code>
+      <code>$firstPart</code>
+      <code>$firstPart</code>
+      <code>$firstPart</code>
+      <code>$firstPart</code>
+      <code>$secondPart</code>
+      <code>$unit</code>
+      <code>$unit</code>
+      <code>$unit</code>
+      <code>$unit</code>
+      <code>$unit</code>
+      <code>$unit</code>
+    </ArgumentTypeCoercion>
+  </file>
+</files>

vendor/sebastian/code-unit/.psalm/config.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<psalm
+    totallyTyped="true"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
+    resolveFromConfigFile="false"
+    errorBaseline=".psalm/baseline.xml"
+>
+    <projectFiles>
+        <directory name="src" />
+        <ignoreFiles>
+            <directory name="vendor" />
+        </ignoreFiles>
+    </projectFiles>
+</psalm>