feat(toolkit): improve logging when sending txs

[ozgb]

Overview

• Fix issue where toolkit would fail to flush logs on exit, causing logs to get lost
• Return exit code non-zero when a send failure occurs

🗹 TODO before merging

• Ready

📌 Submission Checklist

• Changes are backward-compatible (or flagged if breaking)
• Pull request description explains why the change is needed
• Self-reviewed the diff
• I have included a change file, or skipped for this reason:
• If the changes introduce a new feature, I have bumped the node minor version
• Update documentation (if relevant)
• Updated AGENTS.md if build commands, architecture, or workflows changed
• No new todos introduced

🧪 Testing Evidence

Please describe any additional testing aside from CI:

• Additional tests are provided (if possible)

🔱 Fork Strategy

• Node Runtime Update
• Node Client Update
• Other:
• N/A

Links

[github-actions]

KICS version: v2.1.16

Category Results CRITICAL 0 HIGH 0 MEDIUM 123 LOW 12 INFO 85 TRACE 0 TOTAL 220	Metric Values Files scanned 28 Files parsed 28 Files failed to scan 0 Total executed queries 73 Queries failed to execute 0 Execution time 6