Airo TV UX Phase 5: control-row toggles, stats bar, contextual help

[ucguy4u]

Phase 5 — Settings control-row toggles + stats bar + contextual help

Spec: Airo TV UX design (State & persistence; Phasing item 5)

Deliverables

• controlRowVisibilityProvider — per-row visibility, keys iptv_row_<name>_visible; settings section with toggles + Done.
• Stats bar row: reskin existing playback_diagnostic_overlay.dart data as a toggleable shell row — codec, resolution, bitrate. Real data only, no fake stats (Epic [EPG] iptv-org gap analysis: fix schema drift, adopt guides/feeds/logos, self-hosted EPG grab pipeline #950).
• Contextual ? help entries per feature + "What's New" dialog fed from changelog.

Acceptance

• Toggles persist across restart; hidden rows collapse without layout jumps.
• Stats row shows live values from the diagnostics source; hides when no stream.
• Help content reachable from shell; What's New shows current version notes.