Migrate from Deno/JSR to npm publishing

- @sveltejs/package builds dist/ for @eeeooolll/graphiql with three entry
  points (./, ./component, ./splitter)
- Vitest + svelte-check replace Deno test/check; runes shim no longer
  needed since the Svelte plugin compiles .svelte.ts at runtime
- Drop $app/environment dep in Editor.svelte to support non-SvelteKit
  consumers
- Refactor TabBar tab element from nested <button> to role=tab <div> per
  PLAN.md gotcha; svelte-check flagged the invalid HTML
- README now documents npm install, integration patterns for Yoga,
  Apollo, graphql-modules, Hono/Bun/Deno, plus APQ + keyboard table

2 files changed, 13 insertions, 5 deletions

diff --git a/source/library/components/Editor.svelte b/source/library/components/Editor.svelte
index f2bf82d..393812a 100644
--- a/source/library/components/Editor.svelte
+++ b/source/library/components/Editor.svelte
@@ -1,7 +1,6 @@
 <script lang="ts">
   /*** IMPORT ------------------------------------------- ***/
 
-  import { browser } from "$app/environment";
   import { onMount } from "svelte";
   import type { Extension } from "@codemirror/state";
   import type { EditorView } from "@codemirror/view";
@@ -33,7 +32,7 @@
   let view = $state<EditorView | null>(null);
 
   onMount(() => {
-    if (!browser)
+    if (typeof globalThis.document === "undefined")
       return;
 
     let disposed = false;
diff --git a/source/library/components/TabBar.svelte b/source/library/components/TabBar.svelte
index 9c34f20..0bfec02 100644
--- a/source/library/components/TabBar.svelte
+++ b/source/library/components/TabBar.svelte
@@ -130,13 +130,22 @@
   }
 </style>
 
-<div class="tabbar">
+<div class="tabbar" role="tablist">
   {#each tabs as tab (tab.id)}
-    <button
+    <div
+      aria-selected={tab.id === activeId}
       class="tab"
       class:active={tab.id === activeId}
       ondblclick={() => startEditing(tab)}
       onclick={() => onSelect(tab.id)}
+      onkeydown={(e) => {
+        if (e.key === "Enter" || e.key === " ") {
+          e.preventDefault();
+          onSelect(tab.id);
+        }
+      }}
+      role="tab"
+      tabindex="0"
     >
       {#if editingId === tab.id}
         <input
@@ -157,7 +166,7 @@
         class="close"
         onclick={(e) => handleClose(e, tab.id)}
       >×</button>
-    </button>
+    </div>
   {/each}
   <button aria-label="New tab" class="add" onclick={onAdd}>+</button>
 </div>