helwasm: store-on-correct, store button reflects existence, use stored spec

- new read-only export hel_entry(name): the entry's canonical stored form, or ""
- Mark correct now also stores the name (keeps the entry); unmark keeps the stored
  name and just drops the hash (wraps add/rm for an ephemeral entry so the right
  hash is removed)
- Store button shows "Stored ✓" (disabled, ocean outline) when the name is already
  in the catalog, "Store" otherwise
- when a typed name already exists, the field adopts the full stored spec on blur
  (real mode/seq/date/parent) instead of a default-extended parse

helwasm/pkg/helwasm.d.ts

@@ -6,6 +6,14 @@
  */
 export function hel_command(cmd: string): string;
 
+/**
+ * Look up an entry by its exact name and return its canonical stored form
+ * (`name [len]mode seq date comment ^parent`), or "" if it is not in the catalog.
+ * Read-only. The UI uses this to detect "already stored" and to use the real stored
+ * spec (its mode/seq/date/parent) instead of the bare name the user typed.
+ */
+export function hel_entry(name: string): string;
+
 /**
  * Call once at page load: routes Rust panics to the browser console with a
  * readable message + stack instead of an opaque "unreachable" trap.
@@ -38,11 +46,12 @@ export type InitInput = RequestInfo | URL | Response | BufferSource | WebAssembl
 
 export interface InitOutput {
     readonly memory: WebAssembly.Memory;
-    readonly hel_init: () => void;
     readonly hel_command: (a: number, b: number) => [number, number];
+    readonly hel_entry: (a: number, b: number) => [number, number];
     readonly hel_load_script: (a: number, b: number) => [number, number];
     readonly hel_parse: (a: number, b: number) => [number, number];
     readonly hel_parse_name: (a: number, b: number) => [number, number];
+    readonly hel_init: () => void;
     readonly __wbindgen_free: (a: number, b: number, c: number) => void;
     readonly __wbindgen_malloc: (a: number, b: number) => number;
     readonly __wbindgen_realloc: (a: number, b: number, c: number, d: number) => number;