fix(cli-run): rely on continuation markers for completion

Use hook-written continuation marker state to gate run completion checks and remove the noisy event-stream shutdown timeout log in run mode.

src/cli/run/display-chars.ts

@@ -0,0 +1,7 @@
+const isCI = Boolean(process.env.CI || process.env.GITHUB_ACTIONS)
+
+export const displayChars = {
+  treeEnd: isCI ? "`-" : "└─",
+  treeIndent: "   ",
+  treeJoin: isCI ? "   " : "      ",
+} as const