feat: Agent SDK auto-detects Claude Code session — no API key needed locally

ANTHROPIC_API_KEY is optional: Agent SDK uses Claude Code OAuth
session when running locally (detects CLAUDE_CODE_SSE_PORT).
In CI, ANTHROPIC_API_KEY from secrets is used.

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

scripts/qa-agent.ts

@@ -25,7 +25,7 @@ interface AgentOptions {
   qaGuide: string
   outputDir: string
   geminiApiKey: string
-  anthropicApiKey: string
+  anthropicApiKey?: string // Optional — Agent SDK auto-detects Claude Code session
   maxTurns?: number
   timeBudgetMs?: number
 }
@@ -518,7 +518,7 @@ ${issueContext}`
       options: {
         model: 'claude-sonnet-4-6',
         systemPrompt,
-        apiKey: anthropicApiKey,
+        ...(anthropicApiKey ? { apiKey: anthropicApiKey } : {}),
         maxTurns,
         mcpServers: { 'qa-agent': server },
         allowedTools: [

scripts/qa-record.ts

@@ -1938,13 +1938,9 @@ async function main() {
         recordingStartMs = Date.now()
         narrationSegments.length = 0
 
-        // Hybrid agent (Claude + Gemini) — requires ANTHROPIC_API_KEY
+        // Hybrid agent (Claude + Gemini)
+        // Uses ANTHROPIC_API_KEY in CI, or Claude Code OAuth session locally
         const anthropicKey = process.env.ANTHROPIC_API_KEY
-        if (!anthropicKey) {
-          throw new Error(
-            'ANTHROPIC_API_KEY is required for issue reproduction. The Gemini-only agent has been removed due to low success rate.'
-          )
-        }
         const { runHybridAgent } = await import('./qa-agent.js')
         const issueCtx = opts.diffFile
           ? readFileSync(opts.diffFile, 'utf-8').slice(0, 6000)