## Summary
- Fix SSH `-L` port-forward arguments to wrap IPv6 addresses in brackets
(e.g. `-L[::1]:8080:[::1]:80`), so SSH can correctly parse them
- Rewrite `parse_port_forward_spec` to support bracket-wrapped IPv6
tokens like `[::1]:8080:[::1]:80`
- Add diagnostic logging for stdin read failures in the remote server to
aid debugging connection issues
Closes#49009
## Test plan
- [x] New unit tests: `test_parse_port_forward_spec_ipv6`,
`test_port_forward_ipv6_formatting`,
`test_build_command_with_ipv6_port_forward`
- [x] Existing tests pass: `cargo test -p remote --lib
transport::ssh::tests` (6/6)
- [ ] Manual verification: connect via SSH to an IPv6 host with port
forwarding configured
🤖 Generated with [Claude Code](https://claude.com/claude-code)
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Co-authored-by: Claude <noreply@anthropic.com>
