Improve zarvis tool call header wrapping

[edwin-zvs]

Summary

• render zarvis tool-call headers with explicit wrapping instead of relying on terminal soft-wrap
• compact embedded newlines/indentation in args summaries so multiline shell commands do not create large blank horizontal gaps
• make the tool name use a brighter green style while keeping args dim
• add renderer regressions for multiline args wrapping and the brighter tool-name style

Tests

• cargo test -p agentd-cli pty_render::tests::tool_header -- --nocapture
• cargo check -p agentd-cli
• cargo build

Binaries

This PR only changes crates/cli, so the relevant binary is agent. The full workspace was built in debug profile.