Resolves#46461.
- [X] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
---
Verification command (checks how many times /proc/stat is read):
```
sudo bpftrace -e '
tracepoint:syscalls:sys_enter_openat
/str(args->filename) == "/proc/stat" || str(args->filename) == "/proc/uptime"/
{ @[comm, str(args->filename)] = count(); }
interval:s:60 { exit(); }'
```
1.57.0 outputs:
```
@[orbit, /proc/stat]: 1084
```
fleetd built with changes in this PR (and I had to trigger a restart,
otherwise it's 0):
```
@[orbit, /proc/stat]: 3
[...]
@[fleet-desktop, /proc/stat]: 6
```
## Testing
- [X] QA'd all new/changed functionality manually
## fleetd/orbit/Fleet Desktop
- [x] Verified compatibility with the latest released version of Fleet
(see [Must
rule](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/workflows/fleetd-development-and-release-strategy.md))
- [X] If the change applies to only one platform, confirmed that
`runtime.GOOS` is used as needed to isolate changes
- [X] Verified that fleetd runs on macOS, Linux and Windows
- [X] Verified auto-update works from the released version of component
to the new version (see [tools/tuf/test](../tools/tuf/test/README.md))
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Bug Fixes**
* Improved process listing performance on Linux by reducing repeated
system boot-time reads.
* Prevented unnecessary refreshes during frequent process checks,
helping watchdog-style polling run more efficiently.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->