fix: address review findings from BugBot and Seer

1. formatTraceLogs: add trailing newline to JSON output (log.ts)
2. output.ts: fix orphaned JSDoc — move writeFooter docs to writeFooter,
   leave formatFooter with its own one-liner
3. jsonTransformLogOutput: return [] for empty single-fetch, undefined
   only for empty follow-mode batches (log/list.ts)
4. finalize: remove extra trailing newline after formatFooter (log/list.ts)
5. command.ts: move writeFinalization to finally block so streaming table
   footer is written even on mid-stream errors
6. trial/start.ts: check isatty(2) instead of isatty(1) since prompts
   display on stderr after migration

Author: BYK

src/commands/log/list.ts

@@ -462,7 +462,7 @@ function createLogRenderer(): HumanRenderer<LogListResult> {
 
       // Append hint (count, pagination, empty-state message)
       if (hint) {
-        text += `${text ? "\n" : ""}${formatFooter(hint)}\n`;
+        text += `${text ? "\n" : ""}${formatFooter(hint)}`;
       }
 
       return text;
@@ -485,7 +485,9 @@ function jsonTransformLogOutput(
     fields && fields.length > 0 ? filterFields(log, fields) : log;
 
   if (result.logs.length === 0) {
-    return;
+    // Follow mode: suppress empty batches (no JSONL output)
+    // Single-fetch: return empty array for valid JSON
+    return result.jsonl ? undefined : [];
   }
 
   const mapped = result.logs.map(applyFields);

src/commands/trial/start.ts

@@ -191,8 +191,8 @@ async function promptOpenBillingUrl(url: string): Promise<boolean> {
   const qr = await generateQRCode(url);
   log.log(qr);
 
-  // Prompt to open browser if interactive TTY
-  if (isatty(0) && isatty(1)) {
+  // Prompt to open browser if interactive TTY (stdin for input, stderr for display)
+  if (isatty(0) && isatty(2)) {
     const confirmed = await log.prompt("Open in browser?", {
       type: "confirm",
       initial: true,

src/lib/command.ts

@@ -462,6 +462,7 @@ export function buildCommand<
     // Iterate the generator using manual .next() instead of for-await-of
     // so we can capture the return value (done: true result). The return
     // value carries the final `hint` — for-await-of discards it.
+    let hint: string | undefined;
     try {
       const generator = originalFunc.call(
         this,
@@ -474,12 +475,15 @@ export function buildCommand<
         result = await generator.next();
       }
 
-      // Finalize: let the renderer close streaming state (e.g., table
-      // footer), or fall back to the default writeFooter for the hint.
       const returned = result.value as CommandReturn | undefined;
-      writeFinalization(stdout, returned?.hint, cleanFlags.json, renderer);
+      hint = returned?.hint;
     } catch (err) {
       handleOutputError(err);
+    } finally {
+      // Always finalize: close streaming state (e.g., table footer)
+      // even if the generator threw. Without this, a mid-stream error
+      // leaves partial output (e.g., table without bottom border).
+      writeFinalization(stdout, hint, cleanFlags.json, renderer);
     }
   };
 

src/lib/formatters/log.ts

@@ -349,7 +349,7 @@ export function formatTraceLogs(options: FormatTraceLogsOptions): string {
 
   if (asJson) {
     const reversed = [...logs].reverse();
-    return formatJson(fields ? filterFields(reversed, fields) : reversed);
+    return `${formatJson(fields ? filterFields(reversed, fields) : reversed)}\n`;
   }
 
   if (logs.length === 0) {

src/lib/formatters/output.ts

@@ -419,18 +419,15 @@ export function writeOutput<T>(
   }
 }
 
-/**
- * Write a formatted footer hint to stdout.
- * Adds empty line separator and applies muted styling.
- *
- * @param stdout - Writer to output to
- * @param text - Footer text to display
- */
 /** Format footer text (muted, with surrounding newlines). */
 export function formatFooter(text: string): string {
   return `\n${muted(text)}\n`;
 }
 
+/**
+ * Write a formatted footer hint to stdout.
+ * Adds empty line separator and applies muted styling.
+ */
 export function writeFooter(stdout: Writer, text: string): void {
   stdout.write(formatFooter(text));
 }