fix: improve Azure provider auto-detection and validation (#223) (#225)

* fix: improve Azure provider auto-detection and validation (#223)

- Fix detectProvider() to only detect Azure when it has complete config
  (both AZURE_API_KEY and AZURE_RESOURCE_NAME or AZURE_BASE_URL)
- Add validation in validateProviderCredentials() for Azure to provide
  clear error messages when configuration is incomplete
- Update docs/ai-providers.md to clarify Azure requires resource name

* docs: add Azure reasoning options to documentation

docs/ai-providers.md

@@ -80,13 +80,23 @@ SILICONFLOW_BASE_URL=https://api.siliconflow.com/v1  # or https://api.siliconflo
 
 ```bash
 AZURE_API_KEY=your_api_key
+AZURE_RESOURCE_NAME=your-resource-name  # Required: your Azure resource name
 AI_MODEL=your-deployment-name
 ```
 
-Optional custom endpoint:
+Or use a custom endpoint instead of resource name:
 
 ```bash
-AZURE_BASE_URL=https://your-resource.openai.azure.com
+AZURE_API_KEY=your_api_key
+AZURE_BASE_URL=https://your-resource.openai.azure.com  # Alternative to AZURE_RESOURCE_NAME
+AI_MODEL=your-deployment-name
+```
+
+Optional reasoning configuration:
+
+```bash
+AZURE_REASONING_EFFORT=low      # Optional: low, medium, high
+AZURE_REASONING_SUMMARY=detailed  # Optional: none, brief, detailed
 ```
 
 ### AWS Bedrock

lib/ai-providers.ts

@@ -371,8 +371,17 @@ function detectProvider(): ProviderName | null {
             continue
         }
         if (process.env[envVar]) {
+            // Azure requires additional config (baseURL or resourceName)
+            if (provider === "azure") {
+                const hasBaseUrl = !!process.env.AZURE_BASE_URL
+                const hasResourceName = !!process.env.AZURE_RESOURCE_NAME
+                if (hasBaseUrl || hasResourceName) {
                     configuredProviders.push(provider as ProviderName)
                 }
+            } else {
+                configuredProviders.push(provider as ProviderName)
+            }
+        }
     }
 
     if (configuredProviders.length === 1) {
@@ -393,6 +402,18 @@ function validateProviderCredentials(provider: ProviderName): void {
                 `Please set it in your .env.local file.`,
         )
     }
+
+    // Azure requires either AZURE_BASE_URL or AZURE_RESOURCE_NAME in addition to API key
+    if (provider === "azure") {
+        const hasBaseUrl = !!process.env.AZURE_BASE_URL
+        const hasResourceName = !!process.env.AZURE_RESOURCE_NAME
+        if (!hasBaseUrl && !hasResourceName) {
+            throw new Error(
+                `Azure requires either AZURE_BASE_URL or AZURE_RESOURCE_NAME to be set. ` +
+                    `Please set one in your .env.local file.`,
+            )
+        }
+    }
 }
 
 /**