[backport/1.4] frontend: Use linux2rest network probe deltas for tray rates

[joaoantoniocardoso]

This is a backport of #4048 into 1.4.

Before (bug in sampling):

network_before.mp4

After (stable readings):

network_after.mp4

[github-actions]

Automated PR Review

0. Summary

• Verdict: MINOR SUGGESTIONS ✏️

Backport of #4048 to 1.4-dev. Replaces the frontend re-diff of total_* byte counters (which produced negative Mbps on counter resets and flickered against the linux2rest sample cache) with the per-sample received_B / transmitted_B deltas, divided by the linux2rest Sampler interval (hardcoded to 5 s). Also fixes the swapped mdi-cloud-upload/mdi-cloud-download icons on the byte rows, reworks the labels from "Received/Transmitted package" to "Packets received/transmitted", and shows delta / total alongside the totals.

Backport compatibility with 1.4-dev's older linux2rest is fine: core/tools/linux2rest/bootstrap.sh on 1.4-dev pins v0.6.5, which already exposes received_B / transmitted_B / packets_received / packets_transmitted and uses Duration::from_secs(5) for the system Sampler (matches the constant introduced here). Removal of the last_update? field from Network is safe — a grep confirms the only remaining last_update usage is on the Disk type.

8. Documentation

• 8.1 [nit] core/frontend/src/types/system-information/system.ts:84-85 — while updating the JSDoc for received_B / transmitted_B from "package" to "linux2rest/sysinfo probe" wording, the adjacent @param packets_received / @param packets_transmitted lines still say "Number of packages received/transmitted since last probe". The template labels were reworded to "Packets" in this same PR; the JSDoc could follow suit for consistency (very drive-by, not a blocker).

9. Nitpicks / Optional

• 9.1 [nit] core/frontend/src/store/system-information.ts:218 — "Those deltas are already saturating" reads oddly; "already windowed to the Sampler interval" or "already scoped to a 5 s window" would be clearer to future readers.
• 9.2 [nit] core/frontend/src/utils/networking.ts:1-2 — the TODO acknowledges that LINUX2REST_SYSTEM_SAMPLE_INTERVAL_S will silently drift if linux2rest changes cadence. Given this is a backport onto a branch pinned to linux2rest v0.6.5, consider adding a comment near core/tools/linux2rest/bootstrap.sh (or wherever the version is pinned) noting that this constant must be kept in sync — makes the coupling harder to miss during a future linux2rest bump on 1.4.

Generated by PR Review Bot. This is advisory, a human reviewer must still approve.