fix: handle ECONNRESET from sysread on Windows

[toddr-bot]

Summary

On Windows, Perl emulates socketpair(PF_UNIX) via TCP localhost sockets. When the remote end calls close() without shutdown(), a TCP RST is sent instead of FIN, causing sysread() to fail with ECONNRESET rather than returning 0 for EOF. This makes ready() report a read error instead of treating it as a normal disconnect.

This fix treats ECONNRESET the same as ESPIPE (the Solaris EOF equivalent) — both indicate the remote end has disconnected, not a true read error.

Fixes #26

Changes

• Add $!{ECONNRESET} check alongside existing $!{ESPIPE} in ready()'s sysread error handling
• Add test for abrupt close (close without shutdown) to verify graceful handling

Test plan

• New subtest "end-to-end: ERROR response with abrupt close" verifies that ready() handles abrupt disconnects gracefully
• On Unix, the response arrives before EOF so the parse succeeds; on Windows, if RST races with data, the error is handled gracefully instead of dying
• Full test suite shows no regressions (pre-existing platform-specific failures unchanged)

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Generated by Kōan /fix

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Quality Report

Changes: 2 files changed, 41 insertions(+), 1 deletion(-)

Code scan: clean

Tests: passed (OK)

Branch hygiene: clean

Generated by Kōan post-mission quality pipeline