Widen the cherry-picked /diff base (#4839 by @SHL0MS) into one
cross-surface implementation, folding in the review feedback and the
best ideas from the two sibling PRs (#22703, #53527):
- tools/working_diff.py: shared git collection layer — unstaged
(default), staged, and all (vs HEAD) modes; untracked files folded in
via `git diff --no-index` so new files appear as additions (Codex
/diff parity); shlex-split arguments preserve quoted paths.
- CLI: handler moved to hermes_cli/cli_commands_mixin.py per the
current god-file decomposition (dispatch stays in cli.py), renders
through the rich console with a 400-line terminal-flood guard.
- Gateway: _handle_diff_command in gateway/slash_commands.py + dispatch
in gateway/run.py; fenced ```diff output truncated to 60 lines /
3000 chars before the platform senders apply their own per-platform
message clamps (tool-progress-style layered truncation). Localized
strings in all 17 locale catalogs.
- /diff session (from #53527): cumulative checkpoint-baseline diff of
everything Hermes changed, via new CheckpointManager.session_diff();
docstring records the retained-baseline approximation caveat from
review. Works on both surfaces; degrades with an actionable message
when checkpoints are off.
- Slack: /diff routed via /hermes diff (50-slash cap; keeps
telegram-parity test green and /version native).
- Registry: cross-surface CommandDef with staged|all|session
subcommands; docs: slash-commands reference (CLI + gateway tables +
both-surfaces list) and hermes-agent skill reference.
- Tests: tests/tools/test_working_diff.py (real git repos),
tests/hermes_cli/test_diff_command.py (real git + stubbed checkpoint
manager), tests/gateway/test_diff_command.py (end-to-end handler,
real checkpoint store), TestSessionDiff in
tests/tools/test_checkpoint_manager.py.
Salvaged from the /diff PR cluster #4839 + #22703 + #53527.
Co-authored-by: Ninso112 <ninso112@proton.me>
Co-authored-by: Harshkamdar67 <harshkamdar67@gmail.com>
