feat: PromptArch v2.1 - Agentic AI Assist 3-Step Flow + Slides Enhancements

- Implemented Plan -> Approve -> Generate workflow in AIAssist
- Added Plan Review Card with architecture/tech stack preview
- Added Reveal.js Markdown export to SlidesGenerator
- Created /api/ai-assist and /api/slides orchestration routes
- Fixed all syntax errors and build issues
- Maintained premium blue/teal glassmorphism design

app/api/ai-assist/route.ts

@@ -0,0 +1,75 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+// We'll use the environment variables for provider routing
+const schema = z.object({
+    request: z.string().min(10),
+    step: z.enum(["plan", "generate", "preview"]).default("plan"),
+    plan: z.any().optional(),
+    code: z.string().optional(),
+    provider: z.string().optional(),
+    model: z.string().optional()
+});
+
+const STEPS = {
+    plan: `You are an expert software architect. Create a DETAILED DEVELOPMENT PLAN for the following request: "{request}"
+
+Output ONLY a JSON object:
+{
+  "summary": "One sentence overview",
+  "architecture": "High-level components + data flow",
+  "techStack": ["Next.js", "Tailwind", "Lucide Icons"],
+  "files": [
+    {"path": "app/page.tsx", "purpose": "Main UI"},
+    {"path": "components/Preview.tsx", "purpose": "Core logic"}
+  ],
+  "timeline": "Estimate",
+  "risks": ["Potential blockers"]
+}`,
+
+    generate: `You are a Senior Vibe Coder. Execute the following approved plan:
+Plan: {plan}
+
+Generate COMPLETE, PRODUCTION-READY code for all files. 
+Focus on the request: "{request}"
+
+Output ONLY a JSON object:
+{
+  "files": {
+    "app/page.tsx": "// code here",
+    "components/UI.tsx": "// more code"
+  },
+  "explanation": "How it works"
+}`,
+
+    preview: `Convert the following code into a single-file interactive HTML preview (Standalone).
+Use Tailwind CDN. 
+
+Code: {code}
+
+Output ONLY valid HTML.`
+};
+
+export async function POST(req: NextRequest) {
+    try {
+        const body = await req.json();
+        const { request, step, plan, code } = schema.parse(body);
+
+        let prompt = STEPS[step];
+        prompt = prompt.replace("{request}", request);
+        if (plan) prompt = prompt.replace("{plan}", JSON.stringify(plan));
+        if (code) prompt = prompt.replace("{code}", code);
+
+        // In a real scenario, this would call the ModelAdapter/Service
+        // For now, we'll return a structure that the frontend can handle,
+        // instructing it to use the existing streaming adapter for the heavy lifting.
+
+        return NextResponse.json({
+            prompt,
+            step,
+            success: true
+        });
+    } catch (error: any) {
+        return NextResponse.json({ success: false, error: error.message }, { status: 400 });
+    }
+}

app/api/slides/route.ts

@@ -0,0 +1,37 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+const schema = z.object({
+    topic: z.string().min(3),
+    slideCount: z.number().min(3).max(15).default(8),
+    style: z.enum(["professional", "creative", "technical", "pitch"]).default("professional"),
+});
+
+export async function POST(req: NextRequest) {
+    try {
+        const body = await req.json();
+        const { topic, slideCount, style } = schema.parse(body);
+
+        const systemPrompt = `You are an elite presentation designer. Create a visually stunning presentation with ${slideCount} slides about "${topic}".
+    
+Style: ${style}
+
+Output ONLY a sequence of slides separated by "---".
+Format each slide as:
+## [Slide Title]
+- [Bullet Point 1]
+- [Bullet Point 2]
+VISUAL: [Detailed description of image/chart/icon]
+---
+`;
+
+        // The frontend will handle the actual generation call to keep use of the ModelAdapter,
+        // this route serves as the prompt orchestrator.
+        return NextResponse.json({
+            prompt: systemPrompt,
+            success: true
+        });
+    } catch (error: any) {
+        return NextResponse.json({ success: false, error: error.message }, { status: 400 });
+    }
+}