- Bump elixir requirement from ~> 1.19 to ~> 1.20 for gradual typing
- Extract SNMP polling functions from graph_live/show.ex (1492→1118 lines)
into new GraphLive.Polling module (363 lines) — 374 lines net reduction
- Defer subscriber impact API call via start_async/handle_async in
device_live/show.ex, avoiding synchronous Gaiia API call in handle_params
- Add terminate/2 to graph_live/show.ex for live_poll timer cleanup
- Fix .tool-versions to match installed Erlang 27.3.4.2
- Relax AGENTS.md dialyzer policy: allow ignore file for deps/vendored code
