fix: handle backend startup delays with retry logic in auth

web/src/lib/auth.svelte.ts

@@ -24,17 +24,39 @@ class AuthStore {
     return this.state.mode === "authenticated";
   }
 
+  /**
+   * Attempt to load the current user session from the backend.
+   * Only transitions to "unauthenticated" on a definitive 401/403.
+   * Retries indefinitely on transient failures (network errors, 5xx)
+   * so that a slow backend startup doesn't kick the user to login.
+   */
   async init() {
+    const MAX_DELAY_MS = 7_000;
+    let delayMs = 500;
+
+    for (;;) {
       try {
         const response = await fetch("/api/auth/me");
+
         if (response.ok) {
           const user: User = await response.json();
           this.state = { mode: "authenticated", user };
-      } else {
+          return;
-        this.state = { mode: "unauthenticated" };
         }
-    } catch {
+
+        // Definitive rejection — no session or not authorized
+        if (response.status === 401 || response.status === 403) {
           this.state = { mode: "unauthenticated" };
+          return;
+        }
+
+        // Server error (5xx) or unexpected status — retry
+      } catch {
+        // Network error (backend not up yet) — retry
+      }
+
+      await new Promise((r) => setTimeout(r, delayMs));
+      delayMs = Math.min(delayMs * 2, MAX_DELAY_MS);
     }
   }