fix: AI assistant generate_project_cover now uses configured provider

The tool was hardcoded to only check isDalleConfigured(), ignoring
Gemini even when it was the configured image provider. This caused
"DALL-E is not configured" errors for all 13 projects.

Fix: reads imageProvider from SystemSettings and routes to Gemini
or DALL-E accordingly (same logic as the generateCover mutation).

Co-Authored-By: claude-flow <ruv@ruv.net>

packages/api/src/router/assistant-tools.ts

@@ -3813,43 +3813,64 @@ const executors = {
     if (!project) return { error: `Project not found: ${params.projectId}` };
 
     const settings = await ctx.db.systemSettings.findUnique({ where: { id: "singleton" } });
-    if (!isDalleConfigured(settings)) {
-      return { error: "DALL-E is not configured. Set up the DALL-E deployment in Admin → Settings." };
+    const imageProvider = settings?.imageProvider ?? "dalle";
+    const { isGeminiConfigured: isGeminiOk } = await import("../gemini-client.js");
+    const useGemini = imageProvider === "gemini" && isGeminiOk(settings);
+    const useDalle = imageProvider === "dalle" && isDalleConfigured(settings);
+
+    if (!useGemini && !useDalle) {
+      return { error: "No image provider configured. Set up DALL-E or Gemini in Admin → Settings." };
     }
 
     const clientName = project.client?.name ? ` for ${project.client.name}` : "";
     const basePrompt = `Professional cover art for a 3D automotive visualization project: "${project.name}"${clientName}. Style: cinematic, modern, photorealistic CGI rendering, dramatic lighting, studio environment. No text or typography in the image.`;
     const finalPrompt = params.prompt ? `${basePrompt} Additional direction: ${params.prompt}` : basePrompt;
 
-    const dalleClient = createDalleClient(settings!);
-    const model = settings!.aiProvider === "azure" ? settings!.azureDalleDeployment! : "dall-e-3";
+    let coverImageUrl: string;
 
-    try {
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      const response: any = await dalleClient.images.generate({
-        model,
-        prompt: finalPrompt,
-        size: "1024x1024",
-        n: 1,
-        response_format: "b64_json",
-      });
+    if (useGemini) {
+      try {
+        const { generateGeminiImage, parseGeminiError } = await import("../gemini-client.js");
+        coverImageUrl = await generateGeminiImage(
+          settings!.geminiApiKey!,
+          finalPrompt,
+          settings!.geminiModel ?? undefined,
+        );
+      } catch (err) {
+        const { parseGeminiError: parseErr } = await import("../gemini-client.js");
+        return { error: `Gemini error: ${parseErr(err)}` };
+      }
+    } else {
+      const dalleClient = createDalleClient(settings!);
+      const model = settings!.aiProvider === "azure" ? settings!.azureDalleDeployment! : "dall-e-3";
 
-      const b64 = response.data?.[0]?.b64_json;
-      if (!b64) return { error: "No image data returned from DALL-E" };
+      try {
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        const response: any = await dalleClient.images.generate({
+          model,
+          prompt: finalPrompt,
+          size: "1024x1024",
+          n: 1,
+          response_format: "b64_json",
+        });
 
-      const coverImageUrl = `data:image/png;base64,${b64}`;
-      await ctx.db.project.update({ where: { id: params.projectId }, data: { coverImageUrl } });
-
-      return {
-        __action: "invalidate",
-        scope: ["project"],
-        success: true,
-        message: `Generated cover art for project "${project.name}"`,
-        coverImageUrl: coverImageUrl.slice(0, 100) + "...[truncated]",
-      };
-    } catch (err) {
-      return { error: `DALL-E error: ${parseAiError(err)}` };
+        const b64 = response.data?.[0]?.b64_json;
+        if (!b64) return { error: "No image data returned from DALL-E" };
+        coverImageUrl = `data:image/png;base64,${b64}`;
+      } catch (err) {
+        return { error: `DALL-E error: ${parseAiError(err)}` };
+      }
     }
+
+    await ctx.db.project.update({ where: { id: params.projectId }, data: { coverImageUrl } });
+
+    return {
+      __action: "invalidate",
+      scope: ["project"],
+      success: true,
+      message: `Generated cover art for project "${project.name}" using ${useGemini ? "Gemini" : "DALL-E"}`,
+      coverImageUrl: coverImageUrl.slice(0, 100) + "...[truncated]",
+    };
   },
 
   async remove_project_cover(params: { projectId: string }, ctx: ToolContext) {