feat: implement app-side telemetry sender

Add the shared telemetry sender, wire the CLI/server emit points,
and cover the config and completion behavior with tests.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

cli/src/commands/worktree-lib.ts

@@ -224,6 +224,9 @@ export function buildWorktreeConfig(input: {
       ...(authPublicBaseUrl ? { publicBaseUrl: authPublicBaseUrl } : {}),
       disableSignUp: source?.auth.disableSignUp ?? false,
     },
+    telemetry: {
+      enabled: source?.telemetry?.enabled ?? true,
+    },
     storage: {
       provider: source?.storage.provider ?? "local_disk",
       localDisk: {