fix(aionrs): drop malformed tool-call events

[TCP404]

Summary

• Ignore aionrs tool-call and tool-result stream events when the tool name is empty, so malformed calls do not reach the UI or persistence path.
• Strip resumed aionrs session history of empty-name tool uses and their paired tool results before replaying provider history.
• Add regression coverage for empty-name event filtering and session-history sanitization.

Tests

• cargo test -p aionui-ai-agent empty_name
• cargo test -p aionui-ai-agent history_sanitize
• cargo fmt --all --check
• just push -u origin boii/fix/malformed-tool-call-sanitize
  • migration immutability check passed
  • cargo fix / clippy fix completed
  • cargo nextest run --workspace: 6315 passed, 18 skipped