<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#44652
Docs: https://github.com/fleetdm/fleet/pull/46631
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.
- [x] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements), JS
inline code is prevented especially for url redirects, and untrusted
data interpolated into shell scripts/commands is validated against shell
metacharacters.
## Testing
- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually
## Database migrations
- [x] Ensured the correct collation is explicitly set for character
columns (`COLLATE utf8mb4_unicode_ci`).
## New Fleet configuration settings
- [x] Setting(s) is/are explicitly excluded from GitOps
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Route-aware OpenTelemetry trace sampling with tiered default ratios
(very low for select high-volume routes, reduced rate for admin reads,
full sampling otherwise).
* Admin-only GET/PATCH /debug/trace_sampler to view and update sampling
ratios and a runtime "force full" toggle.
* Liveness probe endpoints (/healthz, /version, /metrics) are excluded
from tracing; settings propagate to replicas at runtime without restart.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->