feat(explorer): add event timeseries dict to issue details tool

[jasonyuezhang]

AIML-1375: issue details tool - get time series data for an issue, = event charts in UI

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Copied from getsentry#102119
Original PR: getsentry#102119

[propel-test-bot]

Include issue event-volume time series in get_issue_details response

Adds a small helper (_get_issue_event_timeseries) that fetches bucketed event counts for a specific issue via the /events-stats/ endpoint (dataset issuePlatform). The response is wired into get_issue_details, so callers now receive a new event_timeseries dict alongside the existing issue, event, and tag metadata. Unit tests extended to validate shape of the returned structure.

Key Changes

• Created helper src/sentry/seer/explorer/tools.py::_get_issue_event_timeseries to call /organizations/{slug}/events-stats/ with query issue:{short_id} and return {"count()": {"data": [...]}}
• Invoked helper inside get_issue_details; output exposed as new key event_timeseries in returned payload
• Refactored project-lookup logic: moved org_project_ids query above try/except to avoid duplicate ORM call
• Added extensive assertions in tests/sentry/seer/explorer/test_tools.py to ensure event_timeseries schema validity

Affected Areas

• src/sentry/seer/explorer/tools.py (issue details logic, new endpoint call)
• tests/sentry/seer/explorer/test_tools.py (unit tests)

This summary was automatically generated by @propel-code-bot

[propel-test-bot]

[BestPractice]

The error condition check not (resp.data or {}).get("data") can fail if resp.data is not a dictionary. If the API returns a string, list, or None, calling .get() will raise an AttributeError, causing the function to crash instead of gracefully handling the error.

Suggested change

	if resp.status_code != 200 or not (resp.data or {}).get("data"):
	if resp.status_code != 200 or not isinstance(resp.data, dict) or not resp.data.get("data"):

⚡ Committable suggestion

Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation.

Context for Agents

[**BestPractice**]

The error condition check `not (resp.data or {}).get("data")` can fail if `resp.data` is not a dictionary. If the API returns a string, list, or None, calling `.get()` will raise an AttributeError, causing the function to crash instead of gracefully handling the error.

```suggestion
if resp.status_code != 200 or not isinstance(resp.data, dict) or not resp.data.get("data"):
```

⚡ **Committable suggestion**

Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation.

File: src/sentry/seer/explorer/tools.py
Line: 356