Escape service-supplied text in ts cache purge output #1562

Description

ts cache purge writes text it receives from the service straight to the terminal. A compromised or misconfigured service can embed terminal control sequences (ANSI escapes, carriage returns) that rewrite or hide the operator's output.

Two places in crates/trusted-server-cli/src/commands/cache/purge.rs are affected:

• the success path writes the raw response_body (writeln!(out, "{response_body}"), around line 70);
• the failure path appends response_body.trim() to the purge failed: {status}{hint} error (around lines 83-86).

ts keys (PR #1500) already escapes service text with escape_terminal_text from ad_templates/output.rs; ts cache purge should do the same.

Done when

• Both purge output paths pass service-supplied text through escape_terminal_text.
• Regression tests feed a body containing \u{1b} and \r on success and failure and assert neither reaches the rendered output.

Affected area

CI / Tooling (ts CLI)