bash stdout/stderr and grep matches exceeding 50 KB are now written to
/tmp/harness_out_<call_id>_<suffix>.txt; a 25 KB preview plus the file
path are returned so the model can fetch the rest with the read tool.

Applies consistently to LocalToolRuntime, SandboxToolRuntime, and
E2bToolRuntime — each writes to its own filesystem (/tmp on the host or
inside the sandbox) so the path is always valid for that runtime's read
tool. Shared threshold constant MAX_OUTPUT_BYTES added to tools::mod.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>