Feature request: Allow denylisting specific files/paths in sandbox mode (per-run “deny access” policy)

What feature would you like to see?

In sandbox mode, I’d like the ability to explicitly mark certain files or paths as non-accessible (denylist), even if the sandbox otherwise has access to the workspace filesystem. This is useful for preventing accidental reads of secrets, credentials, private datasets, or unrelated repos during runs.

Additional information

_No response_