fix: add ToolErrorMiddleware (backport #76)

[mergify]

---

This is an automatic backport of pull request #76 done by [Mergify](https://mergify.com).

[greptile-apps]

Confidence Score: 4/5

The agent import and pre-middleware validation paths need fixes before merging.

• The new type import can prevent the agent module from loading on a permitted dependency resolution.
• Initialization validation errors now lose the configuration guidance users need.
• Unexpected exception details are correctly hidden from user-facing responses.

ask_alyf/ask_alyf/agent.py and ask_alyf/ask_alyf/api.py

_{Reviews (1): Last reviewed commit: "fix: add ToolErrorMiddleware (#76)" | Re-trigger Greptile}

[greptile-apps]

Internal Type Import Can Fail

This imports ToolCallRequest from an internal middleware module rather than its public LangChain location. If the permitted LangChain 1.3.x installation does not re-export that type here, importing the agent module raises ImportError and disables every agent entry point; the new tests use SimpleNamespace, so they do not cover this production import.

[greptile-apps]

Configuration Guidance Is Suppressed

Missing API-key or model settings raise actionable ValidationError messages while ask_alyfAgentRunner is being constructed, before tool middleware can handle them. This branch now replaces those messages with a generic response, so a misconfigured installation no longer tells the user what must be configured.

Suggested change

	response = _("I hit an error while processing that request. Please try again.")
	response = (
	str(error).strip()
	if isinstance(error, frappe.ValidationError | frappe.PermissionError)
	else _("I hit an error while processing that request. Please try again.")
	)

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!