fix(announce): make cold-start tracker discovery fast and visible

[MudDev]

Summary

Fixes the cold-start "Waiting for trackers" report: the dashboard sat on that label long after Tor was up, with an empty tracker card.

Cause 1: the boot announce pass was serial and slow

The announce loop walked xites strictly one at a time, and each xite's pass waits out its slowest tracker (75s ceiling). Dozens of xites times the usual dead trackers ground the first pass out for tens of minutes. While it ran, the loop could react to nothing. Measured before the fix: zero Announced lines three minutes after launch. Passes now announce xites four at a time through a semaphore; measured after, the first batch of verdicts (8 xites, real peer counts) landed within a couple of minutes of a cold launch.

Cause 2: nothing re-announced when a transport came up

Onion trackers gated during the pre-Tor boot pass stayed untried until the next periodic pass, up to 20 minutes away. set_tor_status and set_i2p_status now fire trackers_changed on a state move, so the announce loop runs again seconds after Tor or I2P comes up. The notify stores a permit, so a transition during an in-flight pass queues exactly one rerun.

Cause 3: the stats map was empty until announces resolved

A tracker only entered announcerStats after its announce resolved, and overlay-gated entries were filtered out entirely. During the whole cold-start window the map was empty, which is exactly the dashboard's "Waiting for trackers" state. Now:

• A pass seeds every tracker it is about to try as "announcing" and pushes announcerChanged immediately, so rows appear within seconds. A tracker with a verdict keeps showing that verdict while a retry is in flight.
• announcerStats {planned: true} also returns overlay-gated entries, so the health drawer can list every tracker the node plans to try once Tor/I2P is up. The default answer stays gated-free on purpose: shipped dashboards count every returned entry in their health ratio.

Dashboard counterpart

EpixDash-Xite PR (same branch name) polls with planned: true, merges pushed stats instead of replacing them, counts only verdict rows (announced/error) in the health ratio, and renders announcing/gated rows with a status note. Until it is deployed, the shipped dashboard may briefly show "0 of N answering" during the first announce pass instead of "Waiting for trackers"; verdicts land within a minute or two either way.

Testing

• cargo test -p epix-ui --lib tracker: 10 passed.
• Live cold start on Windows 11: tracker rows visible seconds after launch, first verdict batch within ~2 minutes, re-announce observed after Tor bootstrap.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud