feat: consume worktree field from status line hook events

Parse structured WorktreeInfo (name, path, branch, original_repo_directory)
from WorktreeCreate/Remove hook events and emit a dedicated claude:worktree
event. Store per-conversation worktree state and display an emerald branch
badge in the status bar so users can see at a glance which worktree and
branch each session is running on.

Closes #206

src/lib/components/StatusBar.svelte

@@ -29,6 +29,7 @@
 
   let connectionStatus: ConnectionStatus = $state("disconnected");
   let workingDirectory = $state("");
+  let worktreeInfo: import("$lib/types/worktree").WorktreeInfo | null = $state(null);
   let selectedDirectory = $state("/home/naomi");
   let isConnecting = $state(false);
   let grantedToolsList: string[] = $state([]);
@@ -115,6 +116,10 @@
     workingDirectory = dir;
   });
 
+  claudeStore.worktreeInfo.subscribe((info) => {
+    worktreeInfo = info;
+  });
+
   claudeStore.grantedTools.subscribe((tools) => {
     grantedToolsList = Array.from(tools);
   });
@@ -392,6 +397,18 @@
           {workingDirectory}
         </div>
       {/if}
+      {#if worktreeInfo}
+        <div
+          class="flex items-center gap-1 px-2 py-0.5 rounded-full bg-emerald-500/15 border border-emerald-500/30 text-emerald-400 text-xs"
+          title="Worktree: {worktreeInfo.name} | Base: {worktreeInfo.original_repo_directory}"
+        >
+          <svg class="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2"
+              d="M13 10V3L4 14h7v7l9-11h-7z" />
+          </svg>
+          {worktreeInfo.branch}
+        </div>
+      {/if}
     {:else}
       <div class="flex items-center gap-2">
         <span class="text-sm text-gray-600">cwd:</span>