feat(ai): Phase 1 — provider configuration, installer step, admin + company settings

Foundation for the AI chatbot + text generation feature. Phase 1 is infrastructure only: driver plumbing, configuration storage with encrypted API keys, global vs per-company resolution, admin + company UI pages, and an optional installer wizard step. The chat assistant and text-generation WYSIWYG integration come in later phases.

**Driver plumbing (app/Support/Ai/)** — AiDriver abstract, AiDriverFactory, AiException, AiChatResponse DTO, OpenRouterDriver concrete implementation. OpenRouter is the OpenAI-compatible aggregator that unlocks hundreds of models behind one API key and one request shape — ideal as the default v1 driver. Drivers are extensible the same way exchange rate drivers are: the module Registry's generic registerDriver('ai', ...) machinery plus a typed Registry::registerAiDriver() convenience wrapper (shipped in the upstream invoiceshelf/modules package in a paired commit).

**AiConfigurationService** — mirrors MailConfigurationService shape but with one deliberate deviation: API keys are encrypted at the service layer via Crypt::encryptString before persistence. OpenRouter bearer tokens have much bigger blast radius than SMTP passwords. Same settings / company_settings tables, same global-vs-per-company pattern, same use_custom_ai_config override toggle. Resolution order: global ai_enabled must be YES, then the company either overrides via use_custom_ai_config=YES (and can opt out with ai_enabled=NO inside the override) or inherits the global config.

**Controllers** — Admin/Settings/AiConfigurationController (global CRUD + driver list + test connection), Company/Settings/CompanyAiConfigurationController (per-company override + test), Setup/AiConfigurationController (installer wizard step, skippable with explicit ai_enabled=NO). API key is always masked as '********' in GET responses — the frontend submits the placeholder back on save and the backend preserves the stored value.

**Installer wizard** — new optional step 7 'AI' between Mail and Account. Default OFF with a Skip button. MailView.vue now routes to installation.ai instead of installation.account; installation.ai then routes to installation.account. Step order comment updated in routes.ts.

**Admin + Company settings pages** — AdminAiConfigView (no toggle, always global) and AiConfigView (with use_custom_ai_config BaseSwitchSection that auto-saves OFF). Both share AiConfigurationForm which renders the driver selector, API key input with show/hide, driver-specific config_fields (base_url for OpenRouter), and per-role enable toggles with free-text model inputs backed by a datalist of suggested models from driver metadata.

**Bootstrap endpoint** — adds an ai block to the response: { enabled, chat_enabled, text_generation_enabled }. All three are booleans resolved through AiConfigurationService::resolveForCompany(). Never leaks the API key. Frontend feature flags read from bootstrapData.ai to decide whether to show Phase 2/3 UI.

**Bouncer ability** 'manage ai config' added to SettingsPolicy, gated on isSuperAdmin() (same pattern as manage email config, manage pdf config).

**Tests** (22 new) — Unit: AiDriverFactory resolves built-in + Registry-contributed drivers, rejects unknown, merges availableDrivers. AiConfigurationService: encryption round-trip, resolution order (3 cases: global off, inherit global, override with company key, override with opt-out), makeDriver null/instance cases, listDrivers metadata. Feature: admin save + read with api key masking, preserve-on-placeholder behavior, company toggle ON/OFF semantics, bootstrap ai flags reflect resolution, company opt-out path.

372 tests pass (was 350, +22). Pint clean. npm run build clean. Phase 2 (chat assistant + tool calling) and Phase 3 (WYSIWYG text generation popup) are separate follow-up commits — this one is the foundation only.

tests/Unit/AiDriverFactoryTest.php

@@ -0,0 +1,67 @@
+<?php
+
+use App\Support\Ai\AiChatResponse;
+use App\Support\Ai\AiDriver;
+use App\Support\Ai\AiDriverFactory;
+use App\Support\Ai\OpenRouterDriver;
+use InvoiceShelf\Modules\Registry;
+
+test('make resolves the built-in openrouter driver', function () {
+    $driver = AiDriverFactory::make('openrouter', 'fake-key');
+
+    expect($driver)->toBeInstanceOf(OpenRouterDriver::class);
+});
+
+test('make resolves Registry-only drivers via metadata', function () {
+    $fakeClass = new class('', []) extends AiDriver
+    {
+        public function chatCompletion(array $messages, string $model, array $tools = [], array $options = []): AiChatResponse
+        {
+            return new AiChatResponse(message: 'test');
+        }
+
+        public function textCompletion(string $prompt, string $model, array $options = []): string
+        {
+            return 'test';
+        }
+
+        public function validateConnection(): array
+        {
+            return ['ok' => true];
+        }
+    };
+
+    Registry::registerAiDriver('registry_only_ai', [
+        'class' => $fakeClass::class,
+        'label' => 'test.ai.label',
+    ]);
+
+    try {
+        $driver = AiDriverFactory::make('registry_only_ai', 'fake-key');
+        expect($driver)->toBeInstanceOf(AiDriver::class);
+    } finally {
+        unset(Registry::$drivers['ai']['registry_only_ai']);
+    }
+});
+
+test('make throws for unknown drivers', function () {
+    expect(fn () => AiDriverFactory::make('definitely_not_a_real_ai_driver', 'k'))
+        ->toThrow(InvalidArgumentException::class);
+});
+
+test('availableDrivers merges built-in and Registry-registered drivers', function () {
+    Registry::registerAiDriver('extra_ai_driver', [
+        'class' => OpenRouterDriver::class,
+        'label' => 'extra.label',
+    ]);
+
+    try {
+        $available = AiDriverFactory::availableDrivers();
+
+        expect($available)
+            ->toContain('openrouter')
+            ->toContain('extra_ai_driver');
+    } finally {
+        unset(Registry::$drivers['ai']['extra_ai_driver']);
+    }
+});