Add document converter, seeder data structure, and project wiki

- ai-service/convert.py: converts Office/PDF files to markdown with frontmatter
- database/seeders/data/: folder structure for themas, projects, documents, etc.
- database/seeders/data/raw/: drop zone for Office/PDF files to convert
- wiki/: project architecture, concepts, and knowledge graph documentation
- Remove unused Laravel example tests

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/Feature/ExampleTest.php

@@ -1,19 +0,0 @@
-<?php
-
-namespace Tests\Feature;
-
-// use Illuminate\Foundation\Testing\RefreshDatabase;
-use Tests\TestCase;
-
-class ExampleTest extends TestCase
-{
-    /**
-     * A basic test example.
-     */
-    public function test_the_application_returns_a_successful_response(): void
-    {
-        $response = $this->get('/');
-
-        $response->assertStatus(200);
-    }
-}

tests/Unit/ExampleTest.php

@@ -1,16 +0,0 @@
-<?php
-
-namespace Tests\Unit;
-
-use PHPUnit\Framework\TestCase;
-
-class ExampleTest extends TestCase
-{
-    /**
-     * A basic test example.
-     */
-    public function test_that_true_is_true(): void
-    {
-        $this->assertTrue(true);
-    }
-}