test: fix context-sharing suite failure at initialization step

[T72]

Summary

The full safe test suite now fails at tests/test_context_sharing.sh.

Observed

• Suite: test_context_sharing.sh (4/12)
• Failing test: Initialize context with task
• Suite summary: 9 passed, 1 failed

Impact

tests/run_all_tests_safe.sh still exits early and blocks full validation.

Proposed fix

• Reproduce failing assertion in isolated run
• Apply focused fix for context initialization path under current enforcement/runtime behavior
• Re-run suite and full pipeline

[T72]

Resolved by PR #92 (test(windows): stabilize shell suites and safe runner in WSL).