posix: relative paths break after cwd change in wasm bash

[bdsqqq]

when bash runs in @rivet-dev/agent-os-posix under secure-exec, pwd can report the expected worktree cwd while spawned commands still resolve relative paths incorrectly. in the repro at https://github.com/bdsqqq/agent-os-posix-path-repro, cd <worktree> && pwd && cat note.txt prints the worktree path and then fails cat: note.txt: No such file or directory, while cat /absolute/path/to/note.txt succeeds. reproduced on @rivet-dev/agent-os-posix 0.1.0 and 0.1.1.

[NathanFlurry]

Should be fixed in 0.2.0 will confirm