Add outcome-sensitive Bash cwd analysis - #93

Summary

• analyze Bash list success/failure partitions instead of trusting parse order
• model conservative pipeline, substitution, subshell, decoded-wrapper, and cwd-mutator state
• retain resolver-owned path provenance so compatibility paths can be safely rebased, cleared, or recovered
• expand the Bash corpus for joins, wrappers, redirects, CDPATH, transformed operands, and failure-partition recovery

Scope

This completes OpenSpec task 6.5b. Ordered loop-state propagation and removal of the temporary loop-mutation rejection remain in 6.5c. The Web/Mermaid expansion remains tracked as late-stage task 11.8.

Validation

• dotnet build -c Release --no-restore
• dotnet test -c Release --no-build — 1,568 passed
• Bash corpus — 570 passed
• pwsh ./scripts/Add-FileHeaders.ps1 -Verify
• openspec validate v0-3-structured-shell-analysis --strict
• dotnet format --verify-no-changes --no-restore
• slopwatch analyze -d . --hook --no-baseline
• exact staged patch adversarially reviewed: GO (c6c69c039fba0c23db4dbab9e46f0275346c192b7f6e660236da9fd99bb18dde)