fix: structured approvals + ToolCallGroup reactivity

- Replace text-based regex parsing in InlineApproval with structured
  pendingApprovals extracted from request_execution tool results. The tool
  result text is deterministic (not LLM-generated), making UUID extraction
  reliable regardless of how the LLM rephrases the response.

- Fix ToolCallGroup  reactivity: wasActive = active captured initial
  value. Now uses (active) so  re-runs on prop changes.

- Extract approvals in both live streaming (done event) and history loading
  for consistent behavior on resumed sessions.

web/src/pages/Chat.svelte

@@ -114,7 +114,7 @@
             {:else}
               <div class="flex w-full flex-col gap-2">
                 <ToolCallGroup tools={msg.tools} active={$streaming && i === $messages.length - 1} />
-                <InlineApproval text={msg.text} />
+                <InlineApproval approvals={msg.pendingApprovals} />
                 {#if msg.text}
                   <div class="prose-chat max-w-none text-sm leading-relaxed">
                     <!-- eslint-disable-next-line svelte/no-at-html-tags — sanitized via DOMPurify -->