fix(shell): drop POSIX quote-wrap in _shell_escape; strip CR in safe_eval (#84)

[fdaviddpt]

Summary

The shell↔Python variable bridge had two mismatched halves:

• pipeline.shell._shell_escape single-quote-wrapped values per POSIX eval convention.
• scripts/log.sh:safe_eval assigned verbatim via printf -v — no shell expansion, so wrapping quotes survived into the variable.

Invisible on Linux (temp paths contain no shell-unsafe chars, so the escaper returned them unquoted). Broken on Windows: backslash paths got quoted → stored with literal quotes → open('C:\\...txt') actually received "'C:\\...txt'" → OSError: [Errno 22].

Bridge call sites (all hit the same bug):

• save-session.sh:126 extract
• save-session.sh:183 parse-haiku
• save-session.sh:246 parse-haiku (NDC)
• run-consolidation.sh:74 consolidate

Plus: pre-fix log.sh:safe_eval did not strip CR. Python on Windows emits \r\n, so values kept a trailing \r, breaking integer tests in save-session.sh.

Changes

• pipeline/shell.py:_shell_escape → emit verbatim, raise on newline. The parser was always verbatim — now the emitter matches.
• scripts/log.sh:safe_eval → strip trailing \r (Windows CRLF).
• scripts/detect-tools.sh → drop the now-redundant safe_eval override (single source of truth in log.sh).
• tests/test_safe_eval_seam.py (new) → pin the contract both halves must satisfy, including a parametrized Python↔bash roundtrip across Linux paths, Windows backslash paths, spaces, single quotes, and trivial values.
• tests/test_shell.py, tests/test_path_resolution.py → updated to match the new contract.

Why missed by CI

Windows CI matrix exists (ubuntu-latest / macos-latest / windows-latest) but was blind:

1. The CRLF tests in test_path_resolution.py sourced only detect-tools.sh — the file that had the CR strip — never log.sh's broken copy that real orchestrators reach.
2. No end-to-end test of save-session.sh (the script with the shadowing source order).
3. No seam roundtrip between _shell_escape and safe_eval. Both sides tested in isolation; the contract between them was never asserted.

The new test_shell_escape_safe_eval_roundtrip closes that hole.

Test plan

• pytest — 391 passed, 1 skipped, 99% coverage locally.
• New seam tests fail red against main, pass green after fix.
• CI green on ubuntu/macos/windows matrix.

Fixes #84