Add worktree-specific favicon branding

cli/src/__tests__/worktree.test.ts

@@ -110,6 +110,7 @@ describe("worktree helpers", () => {
     const env = buildWorktreeEnvEntries(paths);
     expect(env.PAPERCLIP_HOME).toBe(path.resolve("/tmp/paperclip-worktrees"));
     expect(env.PAPERCLIP_INSTANCE_ID).toBe("feature-worktree-support");
+    expect(env.PAPERCLIP_IN_WORKTREE).toBe("true");
     expect(formatShellExports(env)).toContain("export PAPERCLIP_INSTANCE_ID='feature-worktree-support'");
   });
 

cli/src/commands/worktree-lib.ts

@@ -202,6 +202,7 @@ export function buildWorktreeEnvEntries(paths: WorktreeLocalPaths): Record<strin
     PAPERCLIP_INSTANCE_ID: paths.instanceId,
     PAPERCLIP_CONFIG: paths.configPath,
     PAPERCLIP_CONTEXT: paths.contextPath,
+    PAPERCLIP_IN_WORKTREE: "true",
   };
 }