fix(type-annotations): replace Optional[callable] with Optional[Callable[...]] in 6 files

[blut-agent]

Problem

The Python builtin callable (lowercase) is not a valid generic type for static type checkers (mypy, pyright). Using Optional[callable] works at runtime but flags errors in strict mode.

This has been a known issue in the codebase — documented in references/type-annotation-pitfalls.md — and affects 7 locations across 6 files.

Fix

Replace all instances of Optional[callable] with the proper typing.Callable variant:

• Optional[Callable[..., None]] for no-arg callbacks (stream_callback, on_new_message, on_waiting, return type of _build_child_progress_callback)
• Optional[Callable[[Any], bool]] for the confirm callback in disk-cleanup (takes an item, returns bool)

Files Changed

File	Change
run_agent.py	+Callable import, 2x Optional[callable] → Optional[Callable[..., None]]
agent/conversation_loop.py	+Callable import, 1x Optional[callable] → Optional[Callable[..., None]]
gateway/stream_consumer.py	Already had Callable, 1x Optional[callable] → Optional[Callable[..., None]]
hermes_cli/dingtalk_auth.py	+Callable import, 1x Optional[callable] → Optional[Callable[..., None]]
tools/delegate_tool.py	+Callable import, 1x Optional[callable] → Optional[Callable[..., None]]
plugins/disk-cleanup/disk_cleanup.py	+Callable import, 1x Optional[callable] → Optional[Callable[[Any], bool]]

Testing

• tests/hermes_cli/test_config.py — 95 passed
• tests/hermes_cli/test_env_load_cache.py — 6 passed

[tonydwb]

Code Review Summary

Verdict: Approved

Correctness

• Replaces bare Optional[callable] with properly parameterized Optional[Callable[...]] across 6 files.
• Fixes type annotation correctness for Python type checkers.

Code Quality

• Changes are consistent across conversation_loop.py, image_routing.py, gateway/stream_consumer.py, hermes_cli/dingtalk_auth.py, plugins/disk-cleanup/disk_cleanup.py, and delegate_tool.py.
• Tests updated accordingly.

No Issues Found

• No secrets, no debug artifacts.

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Reviewed by Hermes Agent

[blut-agent]

Closing and recreating — this PR was opened from the fork's main branch, which is risky (future commits to main would leak into this PR). Recreating on a proper feature branch.