v2.6.1 (Lyra): Welcome page, 404 handling, installatie docs, opschoning

Nieuwe features:
- Welkomstpagina bij lege content-map (nieuwe installatie detectie)
- 404-afhandeling binnen actieve theme via admin/static/404.html
- HTTP 404 status bij onbekende pagina's en missende taalprefix

Opschoning:
- Verwijderd: package.json, src/scss/, root .htaccess, themes/demo/
- Verwijderde vendor packages: php-mqtt/client, mustache/mustache
- AGENTS.md samengevoegd naar root, development/AGENTS.md verwijderd
- .gitignore opgeschoond (NPM/node_modules/.sass-cache verwijderd)

Documentatie:
- Installatie instructies toegevoegd aan README (Apache2/Nginx/PHP/composer)
- README en guide versie referenties bijgewerkt naar 2.6.1
- Release notes: docs/release-notes/v2.6.1.md

Tests:
- Pentest: 30/30 geslaagd, 0 vulnerabilities
- WCAG 2.1 AA: 25/25 geslaagd, 100% compliance
- Test scripts gebruiken Apache-URL i.p.v. localhost:8080

vendor/composer/installed.json

@@ -1,5 +1,5 @@
-{
-    "packages": [
+[
+    [
         {
             "name": "composer/ca-bundle",
             "version": "1.5.13",
@@ -718,62 +718,6 @@
             },
             "install-path": "../maxmind/web-service-common"
         },
-        {
-            "name": "mustache/mustache",
-            "version": "v3.0.0",
-            "version_normalized": "3.0.0.0",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/bobthecow/mustache.php.git",
-                "reference": "176b6b21d68516dd5107a63ab71b0050e518b7a4"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/bobthecow/mustache.php/zipball/176b6b21d68516dd5107a63ab71b0050e518b7a4",
-                "reference": "176b6b21d68516dd5107a63ab71b0050e518b7a4",
-                "shasum": ""
-            },
-            "require": {
-                "php": ">=5.6"
-            },
-            "require-dev": {
-                "friendsofphp/php-cs-fixer": "~2.19.3",
-                "yoast/phpunit-polyfills": "^2.0"
-            },
-            "time": "2025-06-28T18:28:20+00:00",
-            "type": "library",
-            "installation-source": "dist",
-            "autoload": {
-                "psr-4": {
-                    "Mustache\\": "src/"
-                },
-                "classmap": [
-                    "src/compat.php"
-                ]
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "authors": [
-                {
-                    "name": "Justin Hileman",
-                    "email": "justin@justinhileman.info",
-                    "homepage": "http://justinhileman.com"
-                }
-            ],
-            "description": "A Mustache implementation in PHP.",
-            "homepage": "https://github.com/bobthecow/mustache.php",
-            "keywords": [
-                "mustache",
-                "templating"
-            ],
-            "support": {
-                "issues": "https://github.com/bobthecow/mustache.php/issues",
-                "source": "https://github.com/bobthecow/mustache.php/tree/v3.0.0"
-            },
-            "install-path": "../mustache/mustache"
-        },
         {
             "name": "myclabs/php-enum",
             "version": "1.8.5",
@@ -1000,66 +944,6 @@
             },
             "install-path": "../nette/utils"
         },
-        {
-            "name": "php-mqtt/client",
-            "version": "v2.3.0",
-            "version_normalized": "2.3.0.0",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/php-mqtt/client.git",
-                "reference": "3d141846753a0adee265680ae073cfb9030f2390"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/php-mqtt/client/zipball/3d141846753a0adee265680ae073cfb9030f2390",
-                "reference": "3d141846753a0adee265680ae073cfb9030f2390",
-                "shasum": ""
-            },
-            "require": {
-                "myclabs/php-enum": "^1.7",
-                "php": "^8.0",
-                "psr/log": "^1.1|^2.0|^3.0"
-            },
-            "require-dev": {
-                "phpunit/php-invoker": "^3.0",
-                "phpunit/phpunit": "^9.0",
-                "squizlabs/php_codesniffer": "^3.5"
-            },
-            "suggest": {
-                "ext-redis": "Required for the RedisRepository"
-            },
-            "time": "2025-09-30T17:53:34+00:00",
-            "type": "library",
-            "installation-source": "dist",
-            "autoload": {
-                "psr-4": {
-                    "PhpMqtt\\Client\\": "src"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "authors": [
-                {
-                    "name": "Marvin Mall",
-                    "email": "marvin-mall@msn.com",
-                    "role": "developer"
-                }
-            ],
-            "description": "An MQTT client written in and for PHP.",
-            "keywords": [
-                "client",
-                "mqtt",
-                "publish",
-                "subscribe"
-            ],
-            "support": {
-                "issues": "https://github.com/php-mqtt/client/issues",
-                "source": "https://github.com/php-mqtt/client/tree/v2.3.0"
-            },
-            "install-path": "../php-mqtt/client"
-        },
         {
             "name": "psr/event-dispatcher",
             "version": "1.0.0",
@@ -1906,6 +1790,6 @@
             "install-path": "../twig/twig"
         }
     ],
-    "dev": true,
-    "dev-package-names": []
-}
+    true,
+    []
+]