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/parsica-php/parsica/tests/Examples/ExcelTest.php

@@ -0,0 +1,131 @@
+<?php declare(strict_types=1);
+/*
+ * This file is part of the Parsica library.
+ *
+ * Copyright (c) 2020 Mathias Verraes <mathias@verraes.net>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Tests\Parsica\Parsica\Examples;
+
+use PHPUnit\Framework\TestCase;
+use Parsica\Parsica\Parser;
+use Parsica\Parsica\PHPUnit\ParserAssertions;
+use function Parsica\Parsica\{alphaChar, between, char, collect, digitChar, skipHSpace1, space, string};
+
+final class ExcelTest extends TestCase
+{
+    use ParserAssertions;
+
+    /** @test */
+    public function spaceOrOperatorDependingOnContext()
+    {
+        // https://twitter.com/Mark_Baker/status/1309919606887374849?s=20
+        // and https://twitter.com/Mark_Baker/status/1309960902482026498?s=20
+        // `=SUM(B7:D7 C6:C8)` where space is the intersection operator for the
+        // intersection between the two ranges B7:D7 and C6:C8 (ie. C7),
+        // and  `=A1 & B1` where the space is simply whitespace and should be ignored
+
+        $parser = $this->excelParser();
+
+
+        $input = "=SUM(B7:D7 C6:C8)";
+        $expected = new Sum(
+            new Intersection(
+                new Range(new Cell("B", "7"), new Cell("D", "7")),
+                new Range(new Cell("C", "6"), new Cell("C", "8")),
+            )
+        );
+        $this->assertParses($input, $parser, $expected);
+
+
+        $input = "=A1 & B1";
+        $expected = new Ampersand(
+            new Cell("A", "1"),
+            new Cell("B", "1"),
+        );
+        $this->assertParses($input, $parser, $expected);
+    }
+
+    private function excelParser(): Parser
+    {
+        $parens = fn(Parser $p): Parser => between(char('('), char(')'), $p);
+        $cell = collect(alphaChar(), digitChar())
+            ->map(fn($o) => new Cell($o[0], $o[1]));
+        $range = collect($cell, char(':'), $cell)
+            ->map(fn($o) => new Range($o[0], $o[2]));
+        $intersection = collect($range, space(), $range)
+            ->map(fn($o) => new Intersection($o[0], $o[2]));
+        $sum = (string('=SUM')->followedBy($parens($intersection)))
+            ->map(fn($o) => new Sum($o));
+
+
+        // consumes space before and after Parser $p
+        $token = fn(Parser $p): Parser => between(skipHSpace1(), skipHSpace1(), $p);
+        $ampersand = char('=')->followedBy(collect(
+            $cell,
+            $token(char('&')),
+            $cell
+        ))->map(fn($o) => new Ampersand($o[0], $o[2]));
+
+
+        return $sum->or($ampersand);
+    }
+
+}
+
+class Cell
+{
+    private $col;
+    private $row;
+
+    function __construct($col, $row)
+    {
+        $this->col = $col;
+        $this->row = $row;
+    }
+}
+class Range
+{
+    private Cell $from;
+    private Cell $to;
+
+    function __construct(Cell $from, Cell $to)
+    {
+        $this->from = $from;
+        $this->to = $to;
+    }
+}
+class Intersection
+{
+    private Range $l;
+    private Range $r;
+
+    function __construct(Range $l, Range $r)
+    {
+        $this->l = $l;
+        $this->r = $r;
+    }
+}
+class Sum
+{
+    private Intersection $intersection;
+
+    function __construct(Intersection $intersection)
+    {
+        $this->intersection = $intersection;
+    }
+}
+class Ampersand
+{
+    private Cell $l;
+    private Cell $r;
+
+    function __construct(Cell $l, Cell $r)
+    {
+        $this->l = $l;
+        $this->r = $r;
+    }
+}