[geroldsteiner67]

Summary

• Reject modal node ping --times 0 during CLI parsing, avoiding a zero-divisor panic in the average-time summary.
• Make the testnet join and mining ping examples runnable: create a separate node directory, obtain a complete bootstrapper multiaddr from the bundled network configuration, and quote the copied address.
• Document that the ping count must be positive.

Validation

• cargo check -p modality-cli-node
• cargo clippy -p modality-cli-node -- -D warnings -A clippy::too_many_arguments
• cargo test -p modality-cli-node ping_count_must_be_positive
• RUSTFLAGS="-D warnings" cargo check --all
• RUSTFLAGS="-D warnings" cargo check --all --tests --examples
• cargo clippy --all -- -D warnings -A clippy::too_many_arguments
• git diff --check