feat(providers): Add provider registry pattern

Replace hardcoded switch statements with dynamic registry pattern.
Providers register with factory using registerProvider() function.

New features:
- registerProvider() function for dynamic registration
- canHandleModel() callback for model routing
- priority field for controlling match order
- aliases support (e.g., 'anthropic' -> 'claude')
- getRegisteredProviderNames() for introspection

Adding new providers now only requires calling registerProvider()
with a factory function and model matching logic.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/server/src/providers/provider-factory.ts

@@ -1,17 +1,43 @@
 /**
  * Provider Factory - Routes model IDs to the appropriate provider
  *
- * This factory implements model-based routing to automatically select
- * the correct provider based on the model string. This makes adding
- * new providers (Cursor, OpenCode, etc.) trivial - just add one line.
+ * Uses a registry pattern for dynamic provider registration.
+ * Providers register themselves on import, making it easy to add new providers.
  */
 
 import { BaseProvider } from './base-provider.js';
-import { ClaudeProvider } from './claude-provider.js';
-import { CursorProvider } from './cursor-provider.js';
 import type { InstallationStatus, ModelDefinition } from './types.js';
 import { CURSOR_MODEL_MAP, type ModelProvider } from '@automaker/types';
 
+/**
+ * Provider registration entry
+ */
+interface ProviderRegistration {
+  /** Factory function to create provider instance */
+  factory: () => BaseProvider;
+  /** Aliases for this provider (e.g., 'anthropic' for 'claude') */
+  aliases?: string[];
+  /** Function to check if this provider can handle a model ID */
+  canHandleModel?: (modelId: string) => boolean;
+  /** Priority for model matching (higher = checked first) */
+  priority?: number;
+}
+
+/**
+ * Provider registry - stores registered providers
+ */
+const providerRegistry = new Map<string, ProviderRegistration>();
+
+/**
+ * Register a provider with the factory
+ *
+ * @param name Provider name (e.g., 'claude', 'cursor')
+ * @param registration Provider registration config
+ */
+export function registerProvider(name: string, registration: ProviderRegistration): void {
+  providerRegistry.set(name.toLowerCase(), registration);
+}
+
 export class ProviderFactory {
   /**
    * Determine which provider to use for a given model
@@ -22,26 +48,26 @@ export class ProviderFactory {
   static getProviderNameForModel(model: string): ModelProvider {
     const lowerModel = model.toLowerCase();
 
-    // Check for explicit cursor prefix
-    if (lowerModel.startsWith('cursor-')) {
-      return 'cursor';
+    // Get all registered providers sorted by priority (descending)
+    const registrations = Array.from(providerRegistry.entries()).sort(
+      ([, a], [, b]) => (b.priority ?? 0) - (a.priority ?? 0)
+    );
+
+    // Check each provider's canHandleModel function
+    for (const [name, reg] of registrations) {
+      if (reg.canHandleModel?.(lowerModel)) {
+        return name as ModelProvider;
+      }
     }
 
-    // Check if it's a known Cursor model ID (without prefix)
-    const cursorModelId = lowerModel.replace('cursor-', '');
-    if (cursorModelId in CURSOR_MODEL_MAP) {
-      return 'cursor';
+    // Fallback: Check for explicit prefixes
+    for (const [name] of registrations) {
+      if (lowerModel.startsWith(`${name}-`)) {
+        return name as ModelProvider;
+      }
     }
 
-    // Check for Claude model patterns
-    if (
-      lowerModel.startsWith('claude-') ||
-      ['opus', 'sonnet', 'haiku'].some((n) => lowerModel.includes(n))
-    ) {
-      return 'claude';
-    }
-
-    // Default to Claude
+    // Default to claude (first registered provider or claude)
     return 'claude';
   }
 
@@ -53,19 +79,25 @@ export class ProviderFactory {
    */
   static getProviderForModel(modelId: string): BaseProvider {
     const providerName = this.getProviderNameForModel(modelId);
+    const provider = this.getProviderByName(providerName);
 
-    if (providerName === 'cursor') {
-      return new CursorProvider();
+    if (!provider) {
+      // Fallback to claude if provider not found
+      const claudeReg = providerRegistry.get('claude');
+      if (claudeReg) {
+        return claudeReg.factory();
+      }
+      throw new Error(`No provider found for model: ${modelId}`);
     }
 
-    return new ClaudeProvider();
+    return provider;
   }
 
   /**
    * Get all available providers
    */
   static getAllProviders(): BaseProvider[] {
-    return [new ClaudeProvider(), new CursorProvider()];
+    return Array.from(providerRegistry.values()).map((reg) => reg.factory());
   }
 
   /**
@@ -74,11 +106,10 @@ export class ProviderFactory {
    * @returns Map of provider name to installation status
    */
   static async checkAllProviders(): Promise<Record<string, InstallationStatus>> {
-    const providers = this.getAllProviders();
     const statuses: Record<string, InstallationStatus> = {};
 
-    for (const provider of providers) {
-      const name = provider.getName();
+    for (const [name, reg] of providerRegistry.entries()) {
+      const provider = reg.factory();
       const status = await provider.detectInstallation();
       statuses[name] = status;
     }
@@ -89,23 +120,26 @@ export class ProviderFactory {
   /**
    * Get provider by name (for direct access if needed)
    *
-   * @param name Provider name (e.g., "claude", "cursor")
+   * @param name Provider name (e.g., "claude", "cursor") or alias (e.g., "anthropic")
    * @returns Provider instance or null if not found
    */
   static getProviderByName(name: string): BaseProvider | null {
     const lowerName = name.toLowerCase();
 
-    switch (lowerName) {
-      case 'claude':
-      case 'anthropic':
-        return new ClaudeProvider();
-
-      case 'cursor':
-        return new CursorProvider();
-
-      default:
-        return null;
+    // Direct lookup
+    const directReg = providerRegistry.get(lowerName);
+    if (directReg) {
+      return directReg.factory();
     }
+
+    // Check aliases
+    for (const [, reg] of providerRegistry.entries()) {
+      if (reg.aliases?.includes(lowerName)) {
+        return reg.factory();
+      }
+    }
+
+    return null;
   }
 
   /**
@@ -115,4 +149,46 @@ export class ProviderFactory {
     const providers = this.getAllProviders();
     return providers.flatMap((p) => p.getAvailableModels());
   }
+
+  /**
+   * Get list of registered provider names
+   */
+  static getRegisteredProviderNames(): string[] {
+    return Array.from(providerRegistry.keys());
+  }
 }
+
+// =============================================================================
+// Provider Registrations
+// =============================================================================
+
+// Import providers for registration side-effects
+import { ClaudeProvider } from './claude-provider.js';
+import { CursorProvider } from './cursor-provider.js';
+
+// Register Claude provider
+registerProvider('claude', {
+  factory: () => new ClaudeProvider(),
+  aliases: ['anthropic'],
+  canHandleModel: (model: string) => {
+    return (
+      model.startsWith('claude-') || ['opus', 'sonnet', 'haiku'].some((n) => model.includes(n))
+    );
+  },
+  priority: 0, // Default priority
+});
+
+// Register Cursor provider
+registerProvider('cursor', {
+  factory: () => new CursorProvider(),
+  canHandleModel: (model: string) => {
+    // Check for explicit cursor prefix
+    if (model.startsWith('cursor-')) {
+      return true;
+    }
+    // Check if it's a known Cursor model ID
+    const modelId = model.replace('cursor-', '');
+    return modelId in CURSOR_MODEL_MAP;
+  },
+  priority: 10, // Higher priority - check Cursor models first
+});