feat: suggest --json in bt view trace text output

The non-JSON text output of `bt view trace` only hinted at `bt view span
--id <row-id>` for full data, which requires N per-span calls. Agents
running `bt view trace` to analyze a trace would either fan out N
requests or pivot to the web UI's CSV export. Add a hint pointing at
`--json` so the full trace payload is reachable in one copy-pasteable
command, alongside the existing next-page hint.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: viadezo1er

src/traces.rs

@@ -4998,6 +4998,12 @@ fn print_trace_text(
         profile_flag_suffix(profile),
         object_ref
     );
+    println!(
+        "For the full trace payload in one call, re-run with --json: `bt view trace --json{} --object-ref {} --trace-id {}`.",
+        profile_flag_suffix(profile),
+        object_ref,
+        trace_id
+    );
     if let Some(cursor) = next_cursor {
         let limit_suffix = if limit != 50 {
             format!(" --limit {limit}")