[#743] Wire TrafficBreached telemetry event

[bolshakov]

#743

TrafficBreached fires when traffic control trips a light from green to red — the circuit just opened. RunCompleted was the only wired event before this; TrafficBreached was defined but never emitted.

• Emits inside the state_store.transition_to_color(Color::RED) guard in Tracker::Request#transition_to_red, so the event fires exactly once per GREEN→RED flip (same dedup invariant the existing notifier call relies on)
• Injects emitter: into Tracker::Request via constructor — same pattern RecoveryProbe already uses
• Adds TrafficControl#name to both built-in policies and the _TrafficControl port; named name to match TrafficRecovery#name on the parallel interface rather than introducing a second term for the same concept. This is a breaking change for custom strategies duck-typing _TrafficControl — adding def name = "your_policy" is the migration

[github-actions]

Review price tag

🟢 75 effective lines — about 9–23 min of focused review (based on 200–500 lines/hour). This is within the range where reviewers find the most issues per line, and small changes usually receive feedback the fastest.

Spread across many files. This PR changes 10 files — more than about 9 in 10 PRs touch. Each extra file is another piece of context a reviewer has to load and hold at once.

Why these numbers?

These minutes are what careful defect-finding costs at 200–500 lines/hour — the rate review studies report, not how long a skim takes. "Effective lines" already exclude generated files and lockfiles. Treat the rates and the 200/400 thresholds as guardrails, not laws.