feat: add display UI with splash screen, dashboard, and RSSI sparkline

Implement full SSD1306 OLED display support:
- Splash screen on boot (1.5s) with project name, version, board
- Dashboard showing radio state, config, counters, RSSI/SNR
- RSSI history sparkline (64-sample ring buffer, 2px-wide bars)
- DisplayOn/DisplayOff host commands routed via dedicated channel
- Pure render functions against generic DrawTarget (no hardware coupling)
- Display on/off control bypasses radio task entirely

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

vendor/winnow/examples/http/bench.rs

@@ -0,0 +1,36 @@
+mod parser;
+mod parser_streaming;
+
+fn one_test(c: &mut criterion::Criterion) {
+    let data = &b"GET / HTTP/1.1
+Host: www.reddit.com
+User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:15.0) Gecko/20100101 Firefox/15.0.1
+Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
+Accept-Language: en-us,en;q=0.5
+Accept-Encoding: gzip, deflate
+Connection: keep-alive
+
+"[..];
+
+    let mut http_group = c.benchmark_group("http");
+    http_group.throughput(criterion::Throughput::Bytes(data.len() as u64));
+    http_group.bench_with_input(
+        criterion::BenchmarkId::new("complete", data.len()),
+        data,
+        |b, data| {
+            b.iter(|| parser::parse(data).unwrap());
+        },
+    );
+    http_group.bench_with_input(
+        criterion::BenchmarkId::new("streaming", data.len()),
+        data,
+        |b, data| {
+            b.iter(|| parser_streaming::parse(data).unwrap());
+        },
+    );
+
+    http_group.finish();
+}
+
+criterion::criterion_group!(http, one_test);
+criterion::criterion_main!(http);