fix: handle 404 errors on list grants for schedules

[btipling]

Wrap 404 errors from OpsGenie API with codes.NotFound so baton-sdk can handle these as warnings instead of errors. This prevents sync failures when a schedule is deleted or renamed in OpsGenie.

Fixes: CX-512

Summary by CodeRabbit

• Bug Fixes
  • Improved handling of third-party on-call API "Not Found" responses: these are now surfaced as clear "Not Found" errors with descriptive messaging instead of a generic failure.
  • Improves diagnostics and user feedback when requested schedules or resources are missing; other error behavior is unchanged.
  • No public interfaces were modified.

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[linear]

CX-512 Opsgenie connector: handle 404 on list-grants

[coderabbitai]

Walkthrough

Adds handling for 404 Not Found responses from the OpsGenie GetOnCalls call in the schedule grants flow, mapping such cases to a gRPC NotFound status with a descriptive message instead of a generic error.

Changes

Cohort / File(s)	Summary
OpsGenie 404 Error Handling pkg/connector/schedule.go	Detects OpsGenie ApiError with HTTP 404 and returns a gRPC NotFound status with a descriptive message; retains prior behavior for non-404 errors.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Poem

🐰 I nudged a 404 from the briar,
Turned its howl to a quiet choir,
gRPC sings what once was hid,
Now not-found hops where code once slid. 🥕

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'fix: handle 404 errors on list grants for schedules' directly and clearly describes the main change: adding 404 error handling to the schedule grants flow.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing touches

• 📝 Generate docstrings

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[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@pkg/connector/schedule.go`:
- Around line 206-210: The current direct type assertion on err to
*ogClient.ApiError in the schedule handling code can miss wrapped errors; import
the "errors" package and replace the assertion with errors.As to unwrap and test
for *ogClient.ApiError (e.g., declare a var apiErr *ogClient.ApiError and call
errors.As(err, &apiErr) ), and if true and apiErr.StatusCode ==
http.StatusNotFound return the same status.Error(codes.NotFound,
fmt.Sprintf(...)) so wrapped ApiError instances are correctly detected; update
imports to include "errors".