Fix job seeker document upload 404ing before profile is saved

upload_document and list_documents both required a pre-existing
job_seeker_profiles row, but nothing creates that row until the user
clicks "Save" on the Basic Information tab. A job seeker who opened
the Documents tab first (or never saved Basic Info) got every upload
silently rejected with a 404, and the earlier fix in frontend-solid
(070c4bd) only addressed a different bug in the dashboard widget - it
never touched this upload path.

upload_document now lazily creates a blank profile row on first
upload instead of 404ing (uploading a verification document doesn't
depend on basic profile fields being filled in). list_documents now
returns an empty list instead of erroring when no profile exists yet,
since that's just the normal empty state for a new job seeker.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/job_seekers/src/handlers.rs

@@ -678,9 +678,27 @@ async fn upload_document(
     auth: AuthUser,
     mut multipart: Multipart,
 ) -> impl IntoResponse {
+    // A job seeker who hasn't saved any basic profile info yet won't have a
+    // job_seeker_profiles row - lazily create a blank one instead of 404ing,
+    // since uploading a verification document doesn't depend on that data.
     let seeker = match JobSeekerRepository::get_by_user_id(&state.pool, auth.user_id).await {
         Ok(Some(s)) => s,
-        Ok(None) => return (StatusCode::NOT_FOUND, Json(serde_json::json!({ "error": "Job seeker profile not found" }))).into_response(),
+        Ok(None) => {
+            let empty_payload = UpsertJobSeekerProfilePayload {
+                full_name: None,
+                location: None,
+                summary: None,
+                experience_years: None,
+                skills: None,
+                resume_url: None,
+                bio: None,
+                custom_data: None,
+            };
+            match JobSeekerRepository::upsert(&state.pool, auth.user_id, empty_payload).await {
+                Ok(s) => s,
+                Err(e) => return (StatusCode::INTERNAL_SERVER_ERROR, Json(serde_json::json!({ "error": e.to_string() }))).into_response(),
+            }
+        }
         Err(e) => return (StatusCode::INTERNAL_SERVER_ERROR, Json(serde_json::json!({ "error": e.to_string() }))).into_response(),
     };
 
@@ -793,9 +811,11 @@ async fn list_documents(
     State(state): State<AppState>,
     auth: AuthUser,
 ) -> impl IntoResponse {
+    // No profile row yet means no documents have ever been uploaded either -
+    // that's a normal empty state, not an error.
     let seeker = match JobSeekerRepository::get_by_user_id(&state.pool, auth.user_id).await {
         Ok(Some(s)) => s,
-        Ok(None) => return (StatusCode::NOT_FOUND, Json(serde_json::json!({ "error": "Job seeker profile not found" }))).into_response(),
+        Ok(None) => return (StatusCode::OK, Json(serde_json::json!({ "data": [] }))).into_response(),
         Err(e) => return (StatusCode::INTERNAL_SERVER_ERROR, Json(serde_json::json!({ "error": e.to_string() }))).into_response(),
     };