Don't count empty Gemini rows as 4/4

.env.example

@@ -24,6 +24,12 @@ KEY_ENCRYPTION_SECRET=generate_with_openssl_rand_-base64_32
 # Optional Gemini API key path (Google AI Studio)
 GEMINI_API_KEY=your_gemini_api_key
 
+# Optional Vertex ADC JSON. Next dotenv and Amplify Hosting env vars truncate
+# unquoted multiline JSON to "{", which used to look like Gemini flaking.
+# Paste a SINGLE LINE JSON string (or wrap the JSON in single quotes).
+# If GEMINI_API_KEY is set, Vertex JSON is unused for chat.
+# GOOGLE_APPLICATION_CREDENTIALS_JSON='{"type":"service_account","project_id":"..."}'
+
 # Public deployments: set to true so visitors must supply their own key (pasted BYOK or saved).
 # Leave unset or false for local dev with server-side .env keys.
 REQUIRE_USER_API_KEYS=false

src/__tests__/byok-route-guards.test.ts

@@ -349,6 +349,125 @@ describe("BYOK-required route guards", () => {
     )
   })
 
+  it("does not count an empty-fail Gemini row as a 4/4 yes-vote", async () => {
+    delete process.env.REQUIRE_USER_API_KEYS
+    generateGeminiVerdictWithApiKeyMock.mockResolvedValue(
+      JSON.stringify({ ...validVerdict, voteSplit: "4/4 unanimous" })
+    )
+    const debate: Message[] = [
+      messages[0],
+      {
+        id: "p1",
+        sender: "perplexity",
+        displayName: "Perplexity",
+        content: "Ship a monolith first.",
+        timestamp: new Date(),
+      },
+      {
+        id: "c1",
+        sender: "claude",
+        displayName: "Claude",
+        content: "Start with a monolith.",
+        timestamp: new Date(),
+      },
+      {
+        id: "g2",
+        sender: "gpt",
+        displayName: "GPT",
+        content: "A well-structured monolith is enough.",
+        timestamp: new Date(),
+      },
+      {
+        id: "gm-fail",
+        sender: "gemini",
+        displayName: "Gemini",
+        content: "Gemini couldn't reply this round.",
+        timestamp: new Date(),
+        failed: true,
+      },
+    ]
+
+    const response = await consensusPOST(
+      jsonRequest("/api/consensus", {
+        messages: debate,
+        locale: "en",
+        responseLength: "medium",
+      }) as never
+    )
+
+    expect(response.status).toBe(200)
+    await expect(response.json()).resolves.toMatchObject({ voteSplit: "3/3 unanimous" })
+    const prompt = generateGeminiVerdictWithApiKeyMock.mock.calls[0]?.[0]?.userPrompt as string
+    expect(prompt).toContain("3 model(s) produced a real reply")
+    expect(prompt).not.toContain("couldn't reply this round")
+  })
+
+  it("does not count a prior-turn Gemini reply when Gemini empty-fails this turn", async () => {
+    delete process.env.REQUIRE_USER_API_KEYS
+    generateGeminiVerdictWithApiKeyMock.mockResolvedValue(
+      JSON.stringify({ ...validVerdict, voteSplit: "4/4 unanimous" })
+    )
+    const debate: Message[] = [
+      messages[0],
+      {
+        id: "gm-old",
+        sender: "gemini",
+        displayName: "Gemini",
+        content: "I answered the first question.",
+        timestamp: new Date(),
+      },
+      {
+        id: "u2",
+        sender: "user",
+        displayName: "You",
+        content: "What about an MVP?",
+        timestamp: new Date(),
+      },
+      {
+        id: "p1",
+        sender: "perplexity",
+        displayName: "Perplexity",
+        content: "Ship a monolith first.",
+        timestamp: new Date(),
+      },
+      {
+        id: "c1",
+        sender: "claude",
+        displayName: "Claude",
+        content: "Start with a monolith.",
+        timestamp: new Date(),
+      },
+      {
+        id: "g2",
+        sender: "gpt",
+        displayName: "GPT",
+        content: "A well-structured monolith is enough.",
+        timestamp: new Date(),
+      },
+      {
+        id: "gm-fail",
+        sender: "gemini",
+        displayName: "Gemini",
+        content: "Gemini couldn't reply this round.",
+        timestamp: new Date(),
+        failed: true,
+      },
+    ]
+
+    const response = await consensusPOST(
+      jsonRequest("/api/consensus", {
+        messages: debate,
+        locale: "en",
+        responseLength: "medium",
+      }) as never
+    )
+
+    expect(response.status).toBe(200)
+    await expect(response.json()).resolves.toMatchObject({ voteSplit: "3/3 unanimous" })
+    const prompt = generateGeminiVerdictWithApiKeyMock.mock.calls[0]?.[0]?.userPrompt as string
+    expect(prompt).toContain("3 model(s) produced a real reply")
+  })
+
   it("ocr proceeds with the saved Gemini key when BYOK is required", async () => {
     authMock.mockResolvedValue({ user: { id: "user-1" } })
     getUserProviderApiKeyMock.mockResolvedValue("user-gemini-key")

src/__tests__/consensus-resolve.test.ts

@@ -43,6 +43,23 @@ describe("humanVerdictError", () => {
     expect(humanVerdictError(new Error("timed out"), "ko")).toMatch(/오래/)
   })
 
+  it("does not treat Vertex credentials JSON errors as a bad API key", () => {
+    expect(
+      humanVerdictError(
+        new Error(
+          "Vertex credentials JSON is invalid or truncated. Put GOOGLE_APPLICATION_CREDENTIALS_JSON on one line or wrap the JSON in single quotes."
+        )
+      )
+    ).toMatch(/credentials JSON/i)
+    expect(
+      humanVerdictError(
+        new Error(
+          "Vertex credentials JSON is invalid or truncated. Put GOOGLE_APPLICATION_CREDENTIALS_JSON on one line or wrap the JSON in single quotes."
+        )
+      )
+    ).not.toMatch(/current key/i)
+  })
+
   it("exports a clear missing-key message", () => {
     expect(NO_CONSENSUS_KEY_MESSAGE).toMatch(/API key/i)
   })