Upgraded Leptos to 0.8. Fixes #1

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.claude/rules/backend.md

@@ -11,7 +11,8 @@ paths:
 ## Server functions
 
 - One file per domain in `src/backend/`. Server-only helpers and their imports go in the `cfg_if! { if #[cfg(feature = "ssr")] { ... }}` block at the top; `#[server]` functions follow below it. Extra server-only imports inside a server fn body are written as local `use` statements.
-- Use plain `#[server]` for new functions (older ones spell out `#[server(Name, "/api", "Url", "name")]`; both end up under `/api`).
+- Use plain `#[server]` for new functions (a few older ones use `#[server(name = Name, prefix = "/api", endpoint = "name")]`; both end up under `/api`). The positional form with `"Url"` no longer compiles. Server functions are registered by `leptos_routes` in `src/main.rs`; there is no separate `/api` route.
+- The current request is `use_context::<leptos_actix::Request>()` (it derefs to `HttpRequest`); extractors go through `leptos_actix::extract().await?`.
 - Return `Result<ApiResponse<T>, ServerFnError>`. Expected/business failures are `Ok(ApiResponse::Error("English message".to_string()))` — the client passes that string through `trl()`, so add it to the catalogue. `Err(ServerFnError)` is for real failures (DB down etc.).
 - A function used with `<DataForm>` / `<QuestionDialog>` must return `ApiResponse<()>` and take the form entity as a single struct argument; its name is the prefix of the form field names (`company: Company` ↔ `name="company[name]"`).
 - For `<DataForm>`, implement `ForValidation` for the generated struct (PascalCase of the fn name) right below the function: