fix: rename model registry files to match autoloader convention

The custom autoloader converts PRAutoBlogger_OpenRouter_Model_Registry
to class-open-router-model-registry.php (hyphen between Open and Router),
but the files were named class-openrouter-model-registry.php. This caused
a fatal "Class not found" error on every uncached page load.

Renames:
- class-openrouter-model-registry.php → class-open-router-model-registry.php
- class-openrouter-model-normalizer.php → class-open-router-model-normalizer.php

Updates @see references in interface, ARCHITECTURE.md, and CHANGELOG.md.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

includes/services/class-open-router-model-normalizer.php

@@ -11,7 +11,7 @@ declare(strict_types=1);
  * Triggered by: PRAutoBlogger_OpenRouter_Model_Registry::refresh().
  * Dependencies: None — pure data transformation, no I/O.
  *
- * @see services/class-openrouter-model-registry.php — Sole consumer.
+ * @see services/class-open-router-model-registry.php — Sole consumer.
  * @see interface-model-registry.php                  — Defines the normalized record shape.
  * @see ARCHITECTURE.md                               — Capability vocabulary.
  */

includes/services/class-open-router-model-registry.php

@@ -17,7 +17,7 @@ declare(strict_types=1);
  *               PRAutoBlogger_OpenRouter_Model_Normalizer.
  *
  * @see interface-model-registry.php               — Interface.
- * @see class-openrouter-model-normalizer.php       — Normalization logic.
+ * @see class-open-router-model-normalizer.php       — Normalization logic.
  * @see class-prautoblogger.php                     — Hooks the refresh action.
  * @see ARCHITECTURE.md                             — AI Model Registries section.
  */

includes/services/interface-model-registry.php

@@ -4,7 +4,7 @@ declare(strict_types=1);
 /**
  * Contract for a provider-specific AI model registry.
  *
- * Phase 1 (v1): single implementation for OpenRouter (`class-openrouter-model-registry.php`).
+ * Phase 1 (v1): single implementation for OpenRouter (`class-open-router-model-registry.php`).
  * Phase 3: a second implementation wraps Cloudflare Workers AI FLUX model data. A
  * higher-level dispatcher iterates registered registries, calls each with the same
  * capability, and unions the results — the per-registry interface stays unchanged.
@@ -19,7 +19,7 @@ declare(strict_types=1);
  *               (commit 3), daily cron via the main plugin loader.
  * Dependencies: None at interface level — implementations wrap an HTTP API.
  *
- * @see services/class-openrouter-model-registry.php — Default implementation.
+ * @see services/class-open-router-model-registry.php — Default implementation.
  * @see admin/fields/class-openrouter-model-field.php — Field renderer that queries this interface.
  * @see ARCHITECTURE.md                               — AI Model Registries section.
  */