feat: add Osaurus API authentication support

- Add OSAURUS_API_KEY config for Bearer token authentication
- Handle Osaurus streaming format responses even with stream: false
- Update .env.example with Osaurus configuration

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

src/proxy/forward.ts

@@ -16,30 +16,93 @@ export async function forwardChatRequest(requestBody: any): Promise<any> {
   requestBody = normalizeRequest(requestBody);
 
   logger.info(`Forwarding chat request to ${targetEndpoint} for model: ${requestBody.model}`);
-  logger.info(`Request body: ${JSON.stringify(requestBody, null, 2)}`);
+
+  const headers: Record<string, string> = {
+    'Content-Type': 'application/json',
+    'Accept': 'application/json'
+  };
+
+  // Add Authorization header if API key is configured
+  if (config.apiKey) {
+    headers['Authorization'] = `Bearer ${config.apiKey}`;
+  }
 
   const options: RequestInit = {
     method: 'POST',
-    headers: {
-      'Content-Type': 'application/json',
-      'Accept': 'application/json'
-    },
+    headers,
     body: JSON.stringify(requestBody)
   };
 
   const response = await fetch(targetEndpoint, options);
-  
+
   if (!response.ok) {
     const errorText = await response.text();
     logger.error(`Ollama upstream error ${response.status}: ${errorText}`);
     throw new Error(`Upstream returned ${response.status}: ${errorText}`);
   }
 
-  // Assuming it's not a stream for now
-  const responseData = await response.json();
-  
+  // Handle response - Osaurus may return streaming format even with stream: false
+  const responseText = await response.text();
+
+  // Try to parse as single JSON first (standard Ollama behavior)
+  let responseData: any;
+  try {
+    responseData = JSON.parse(responseText);
+  } catch (e) {
+    // If that fails, it might be streaming format (multiple JSON lines)
+    // Combine all chunks into a single response
+    const lines = responseText.trim().split('\n').filter(line => line.trim());
+    if (lines.length === 0) {
+      throw new Error('Empty response from upstream');
+    }
+
+    // Combine streaming chunks
+    let combinedContent = '';
+    let lastChunk: any = null;
+    let message: any = { role: 'assistant', content: '' };
+
+    for (const line of lines) {
+      try {
+        const chunk = JSON.parse(line);
+        lastChunk = chunk;
+        if (chunk.message?.content) {
+          combinedContent += chunk.message.content;
+        }
+        // Preserve tool_calls from any chunk
+        if (chunk.message?.tool_calls) {
+          message.tool_calls = chunk.message.tool_calls;
+        }
+        // Preserve thinking if present
+        if (chunk.message?.thinking) {
+          message.thinking = chunk.message.thinking;
+        }
+      } catch (parseError) {
+        logger.warn(`Failed to parse chunk: ${line}`);
+      }
+    }
+
+    message.content = combinedContent;
+
+    // Build the combined response using the last chunk's metadata
+    responseData = {
+      model: lastChunk?.model || requestBody.model,
+      created_at: lastChunk?.created_at || new Date().toISOString(),
+      message,
+      done: true,
+      done_reason: lastChunk?.done_reason || 'stop',
+      total_duration: lastChunk?.total_duration,
+      load_duration: lastChunk?.load_duration,
+      prompt_eval_count: lastChunk?.prompt_eval_count,
+      prompt_eval_duration: lastChunk?.prompt_eval_duration,
+      eval_count: lastChunk?.eval_count,
+      eval_duration: lastChunk?.eval_duration,
+    };
+
+    logger.info(`Combined ${lines.length} streaming chunks into single response`);
+  }
+
   // Rewrite if necessary
   const rewrittenData = rewriteResponse(responseData);
-  
+
   return rewrittenData;
 }