feat: implement 4 project type flows with unique AI experiences

- New multi-step CreateProjectFlow replaces 2-step modal with TypeSelector
  and 4 setup components (Fresh Idea, Chat Import, Code Import, Migrate)
- overview/page.tsx routes to unique main component per creationMode
- FreshIdeaMain: wraps AtlasChat with post-discovery decision banner
  (Generate PRD vs Plan MVP Test)
- ChatImportMain: 3-stage flow (intake → extracting → review) with
  editable insight buckets (decisions, ideas, questions, architecture, users)
- CodeImportMain: 4-stage flow (input → cloning → mapping → surfaces)
  with architecture map and surface selection
- MigrateMain: 5-stage flow with audit, review, planning, and migration
  plan doc with checkbox-tracked tasks and non-destructive warning banner
- New API routes: analyze-chats, analyze-repo, analysis-status,
  generate-migration-plan (all using Gemini)
- ProjectShell: accepts creationMode prop, filters/renames tabs per type
  (code-import hides PRD, migration hides PRD/Grow/Insights, renames Atlas tab)
- Right panel adapts content based on creationMode

Made-with: Cursor

components/project-main/FreshIdeaMain.tsx

@@ -0,0 +1,133 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import { AtlasChat } from "@/components/AtlasChat";
+import { useRouter, useParams } from "next/navigation";
+
+const DISCOVERY_PHASES = [
+  "big_picture",
+  "users_personas",
+  "features_scope",
+  "business_model",
+  "screens_data",
+  "risks_questions",
+];
+
+interface FreshIdeaMainProps {
+  projectId: string;
+  projectName: string;
+}
+
+export function FreshIdeaMain({ projectId, projectName }: FreshIdeaMainProps) {
+  const router = useRouter();
+  const params = useParams();
+  const workspace = params?.workspace as string;
+
+  const [savedPhaseIds, setSavedPhaseIds] = useState<Set<string>>(new Set());
+  const [allDone, setAllDone] = useState(false);
+  const [prdLoading, setPrdLoading] = useState(false);
+  const [dismissed, setDismissed] = useState(false);
+
+  useEffect(() => {
+    const poll = () => {
+      fetch(`/api/projects/${projectId}/save-phase`)
+        .then(r => r.json())
+        .then(d => {
+          const ids = new Set<string>((d.phases ?? []).map((p: { phase: string }) => p.phase));
+          setSavedPhaseIds(ids);
+          const done = DISCOVERY_PHASES.every(id => ids.has(id));
+          setAllDone(done);
+        })
+        .catch(() => {});
+    };
+    poll();
+    const interval = setInterval(poll, 8_000);
+    return () => clearInterval(interval);
+  }, [projectId]);
+
+  const handleGeneratePRD = async () => {
+    if (prdLoading) return;
+    setPrdLoading(true);
+    try {
+      router.push(`/${workspace}/project/${projectId}/prd`);
+    } finally {
+      setPrdLoading(false);
+    }
+  };
+
+  const handleMVP = () => {
+    router.push(`/${workspace}/project/${projectId}/build`);
+  };
+
+  return (
+    <div style={{ height: "100%", display: "flex", flexDirection: "column", position: "relative" }}>
+      {/* Decision banner — shown when all 6 phases are saved */}
+      {allDone && !dismissed && (
+        <div style={{
+          background: "linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%)",
+          padding: "18px 28px",
+          display: "flex", alignItems: "center", justifyContent: "space-between",
+          gap: 16, flexShrink: 0, flexWrap: "wrap",
+          borderBottom: "1px solid #333",
+        }}>
+          <div>
+            <div style={{ fontSize: "0.88rem", fontWeight: 700, color: "#fff", fontFamily: "Outfit, sans-serif", marginBottom: 3 }}>
+              ✦ Discovery complete — what's next?
+            </div>
+            <div style={{ fontSize: "0.75rem", color: "#a09a90", fontFamily: "Outfit, sans-serif" }}>
+              Atlas has captured all 6 discovery phases. Choose your next step.
+            </div>
+          </div>
+          <div style={{ display: "flex", gap: 10, flexShrink: 0 }}>
+            <button
+              onClick={handleGeneratePRD}
+              disabled={prdLoading}
+              style={{
+                padding: "10px 20px", borderRadius: 8, border: "none",
+                background: "#fff", color: "#1a1a1a",
+                fontSize: "0.84rem", fontWeight: 700,
+                fontFamily: "Outfit, sans-serif", cursor: "pointer",
+                transition: "opacity 0.12s",
+              }}
+              onMouseEnter={e => (e.currentTarget.style.opacity = "0.88")}
+              onMouseLeave={e => (e.currentTarget.style.opacity = "1")}
+            >
+              {prdLoading ? "Navigating…" : "Generate PRD →"}
+            </button>
+            <button
+              onClick={handleMVP}
+              style={{
+                padding: "10px 20px", borderRadius: 8,
+                border: "1px solid rgba(255,255,255,0.2)",
+                background: "transparent", color: "#fff",
+                fontSize: "0.84rem", fontWeight: 600,
+                fontFamily: "Outfit, sans-serif", cursor: "pointer",
+                transition: "background 0.12s",
+              }}
+              onMouseEnter={e => (e.currentTarget.style.background = "rgba(255,255,255,0.08)")}
+              onMouseLeave={e => (e.currentTarget.style.background = "transparent")}
+            >
+              Plan MVP Test →
+            </button>
+            <button
+              onClick={() => setDismissed(true)}
+              style={{
+                background: "none", border: "none", cursor: "pointer",
+                color: "#666", fontSize: "1rem", padding: "4px 6px",
+                fontFamily: "Outfit, sans-serif",
+              }}
+              title="Dismiss"
+            >
+              ×
+            </button>
+          </div>
+        </div>
+      )}
+
+      <AtlasChat
+        projectId={projectId}
+        projectName={projectName}
+      />
+    </div>
+  );
+}