Neon / portal template support (#713)

TODOs:
- [x] Do restart when checkout / restore if there is a DB
- [x] List all branches (branch id, name, date)
- [x] Allow checking out versions with no DB
- [x] safeguard to never delete main branches
- [x] create app hook for neon template
- [x] weird UX with connector on configure panel
- [x] tiny neon logo in connector
- [x] deploy to vercel
- [x] build forgot password page
- [x] what about email setup
- [x] lots of imgix errors
- [x] edit file - db snapshot
- [x] DYAD_DISABLE_DB_PUSH
- [ ] update portal doc
- [x] switch preview branch to be read-only endpoint
- [x] disable supabase sys prompt if neon is enabled
- [ ] https://payloadcms.com/docs/upload/storage-adapters
- [x] need to use main branch...

Phase 2?
- [x] generate DB migrations

src/components/CreateAppDialog.tsx

@@ -0,0 +1,137 @@
+import React, { useState } from "react";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import { useCreateApp } from "@/hooks/useCreateApp";
+import { useCheckName } from "@/hooks/useCheckName";
+import { useSetAtom } from "jotai";
+import { selectedAppIdAtom } from "@/atoms/appAtoms";
+import { NEON_TEMPLATE_IDS, Template } from "@/shared/templates";
+
+import { useRouter } from "@tanstack/react-router";
+
+import { Loader2 } from "lucide-react";
+import { neonTemplateHook } from "@/client_logic/template_hook";
+import { showError } from "@/lib/toast";
+
+interface CreateAppDialogProps {
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+  template: Template | undefined;
+}
+
+export function CreateAppDialog({
+  open,
+  onOpenChange,
+  template,
+}: CreateAppDialogProps) {
+  const setSelectedAppId = useSetAtom(selectedAppIdAtom);
+  const [appName, setAppName] = useState("");
+  const [isSubmitting, setIsSubmitting] = useState(false);
+  const { createApp } = useCreateApp();
+  const { data: nameCheckResult } = useCheckName(appName);
+  const router = useRouter();
+  const handleSubmit = async (e: React.FormEvent) => {
+    e.preventDefault();
+
+    if (!appName.trim()) {
+      return;
+    }
+
+    if (nameCheckResult?.exists) {
+      return;
+    }
+
+    setIsSubmitting(true);
+    try {
+      const result = await createApp({ name: appName.trim() });
+      if (template && NEON_TEMPLATE_IDS.has(template.id)) {
+        await neonTemplateHook({
+          appId: result.app.id,
+          appName: result.app.name,
+        });
+      }
+      setSelectedAppId(result.app.id);
+      // Navigate to the new app's first chat
+      router.navigate({
+        to: "/chat",
+        search: { id: result.chatId },
+      });
+      setAppName("");
+      onOpenChange(false);
+    } catch (error) {
+      showError(error as any);
+      // Error is already handled by createApp hook or shown above
+      console.error("Error creating app:", error);
+    } finally {
+      setIsSubmitting(false);
+    }
+  };
+
+  const isNameValid = appName.trim().length > 0;
+  const nameExists = nameCheckResult?.exists;
+  const canSubmit = isNameValid && !nameExists && !isSubmitting;
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent className="sm:max-w-[425px]">
+        <DialogHeader>
+          <DialogTitle>Create New App</DialogTitle>
+          <DialogDescription>
+            {`Create a new app using the ${template?.title} template.`}
+          </DialogDescription>
+        </DialogHeader>
+
+        <form onSubmit={handleSubmit}>
+          <div className="grid gap-4 py-4">
+            <div className="grid gap-2">
+              <Label htmlFor="appName">App Name</Label>
+              <Input
+                id="appName"
+                value={appName}
+                onChange={(e) => setAppName(e.target.value)}
+                placeholder="Enter app name..."
+                className={nameExists ? "border-red-500" : ""}
+                disabled={isSubmitting}
+              />
+              {nameExists && (
+                <p className="text-sm text-red-500">
+                  An app with this name already exists
+                </p>
+              )}
+            </div>
+          </div>
+
+          <DialogFooter>
+            <Button
+              type="button"
+              variant="outline"
+              onClick={() => onOpenChange(false)}
+              disabled={isSubmitting}
+            >
+              Cancel
+            </Button>
+            <Button
+              type="submit"
+              disabled={!canSubmit}
+              className="bg-indigo-600 hover:bg-indigo-700"
+            >
+              {isSubmitting && (
+                <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+              )}
+              {isSubmitting ? "Creating..." : "Create App"}
+            </Button>
+          </DialogFooter>
+        </form>
+      </DialogContent>
+    </Dialog>
+  );
+}