Fix Edit in Planner: create session via API, avoid URL size limit

GPX data was being encoded in URL params, causing HTTP 431 (Request
Header Fields Too Large). Now the Journal creates a Planner session
via POST to /api/sessions with GPX in the request body, then
redirects to the session URL (154 chars vs 100KB+).

Also moved edit-in-planner logic to dedicated API route for proper
JSON response handling.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/journal/app/routes.ts

@@ -13,5 +13,6 @@ export default [
   route("routes/:id", "routes/routes.$id.tsx"),
   route("routes/:id/edit", "routes/routes.$id.edit.tsx"),
   route("api/routes/:id/callback", "routes/api.routes.$id.callback.ts"),
+  route("api/routes/:id/edit-in-planner", "routes/api.routes.$id.edit-in-planner.ts"),
   route("users/:username", "routes/users.$username.tsx"),
 ] satisfies RouteConfig;

apps/journal/app/routes/api.routes.$id.edit-in-planner.ts

@@ -0,0 +1,41 @@
+import { data } from "react-router";
+import type { Route } from "./+types/api.routes.$id.edit-in-planner";
+import { getSessionUser } from "~/lib/auth.server";
+import { getRouteWithVersions } from "~/lib/routes.server";
+import { createRouteToken } from "~/lib/jwt.server";
+
+export async function action({ params, request }: Route.ActionArgs) {
+  const user = await getSessionUser(request);
+  if (!user) return data({ error: "Not authenticated" }, { status: 401 });
+
+  const route = await getRouteWithVersions(params.id);
+  if (!route) return data({ error: "Route not found" }, { status: 404 });
+  if (route.ownerId !== user.id) return data({ error: "Not authorized" }, { status: 403 });
+
+  const token = await createRouteToken(params.id);
+  const origin = process.env.ORIGIN ?? "http://localhost:3000";
+  const callbackUrl = `${origin}/api/routes/${params.id}/callback`;
+  const plannerUrl = process.env.PLANNER_URL ?? "http://localhost:3001";
+  const returnUrl = `${origin}/routes/${params.id}`;
+
+  // Create Planner session via API (POST body, not URL params)
+  const sessionResp = await fetch(`${plannerUrl}/api/sessions`, {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify({
+      callbackUrl,
+      callbackToken: token,
+      gpx: route.gpx ?? undefined,
+    }),
+  });
+
+  if (!sessionResp.ok) {
+    return data({ error: "Failed to create Planner session" }, { status: 502 });
+  }
+
+  const session = (await sessionResp.json()) as { url: string };
+
+  return data({
+    url: `${plannerUrl}${session.url}?returnUrl=${encodeURIComponent(returnUrl)}`,
+  });
+}

apps/journal/app/routes/routes.$id.tsx

@@ -3,7 +3,6 @@ import { data, redirect } from "react-router";
 import type { Route } from "./+types/routes.$id";
 import { getSessionUser } from "~/lib/auth.server";
 import { getRouteWithVersions, deleteRoute, updateRoute } from "~/lib/routes.server";
-import { createRouteToken } from "~/lib/jwt.server";
 
 
 export async function loader({ params, request }: Route.LoaderArgs) {
@@ -75,29 +74,6 @@ export async function action({ params, request }: Route.ActionArgs) {
     });
   }
 
-  if (intent === "edit-in-planner") {
-    const route = await getRouteWithVersions(params.id);
-    if (!route) return data({ error: "Route not found" }, { status: 404 });
-
-    const token = await createRouteToken(params.id);
-    const origin = process.env.ORIGIN ?? "http://localhost:3000";
-    const callbackUrl = `${origin}/api/routes/${params.id}/callback`;
-    const plannerUrl = process.env.PLANNER_URL ?? "http://localhost:3001";
-
-    const plannerParams = new URLSearchParams({
-      callback: callbackUrl,
-      token,
-      returnUrl: `${origin}/routes/${params.id}`,
-    });
-
-    // If route has GPX, include it
-    if (route.gpx) {
-      plannerParams.set("gpx", encodeURIComponent(route.gpx));
-    }
-
-    return data({ redirect: `${plannerUrl}/new?${plannerParams}` });
-  }
-
   return data({ error: "Unknown action" }, { status: 400 });
 }
 
@@ -113,12 +89,10 @@ export default function RouteDetailPage({ loaderData }: Route.ComponentProps) {
   const handleEditInPlanner = useCallback(async () => {
     setEditLoading(true);
     try {
-      const formData = new FormData();
-      formData.set("intent", "edit-in-planner");
-      const resp = await fetch(`/routes/${route.id}`, { method: "POST", body: formData });
+      const resp = await fetch(`/api/routes/${route.id}/edit-in-planner`, { method: "POST" });
       const result = await resp.json();
-      if (result.redirect) {
-        window.location.href = result.redirect;
+      if (result.url) {
+        window.location.href = result.url;
       }
     } finally {
       setEditLoading(false);