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/strsim/benches/benches.rs

@@ -0,0 +1,95 @@
+//! Benchmarks for strsim.
+
+#![feature(test)]
+
+extern crate strsim;
+extern crate test;
+use self::test::Bencher;
+
+#[bench]
+fn bench_hamming(bencher: &mut Bencher) {
+    let a = "ACAAGATGCCATTGTCCCCCGGCCTCCTGCTGCTGCTGCTCTCCGGGG";
+    let b = "CCTGGAGGGTGGCCCCACCGGCCGAGACAGCGAGCATATGCAGGAAGC";
+    bencher.iter(|| {
+        strsim::hamming(a, b).unwrap();
+    })
+}
+
+#[bench]
+fn bench_jaro(bencher: &mut Bencher) {
+    let a = "Philosopher Friedrich Nietzsche";
+    let b = "Philosopher Jean-Paul Sartre";
+    bencher.iter(|| {
+        strsim::jaro(a, b);
+    })
+}
+
+#[bench]
+fn bench_jaro_winkler(bencher: &mut Bencher) {
+    let a = "Philosopher Friedrich Nietzsche";
+    let b = "Philosopher Jean-Paul Sartre";
+    bencher.iter(|| {
+        strsim::jaro_winkler(a, b);
+    })
+}
+
+#[bench]
+fn bench_levenshtein(bencher: &mut Bencher) {
+    let a = "Philosopher Friedrich Nietzsche";
+    let b = "Philosopher Jean-Paul Sartre";
+    bencher.iter(|| {
+        strsim::levenshtein(a, b);
+    })
+}
+
+#[bench]
+fn bench_levenshtein_on_u8(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        strsim::generic_levenshtein(&vec![0u8; 30], &vec![7u8; 31]);
+    })
+}
+
+#[bench]
+fn bench_normalized_levenshtein(bencher: &mut Bencher) {
+    let a = "Philosopher Friedrich Nietzsche";
+    let b = "Philosopher Jean-Paul Sartre";
+    bencher.iter(|| {
+        strsim::normalized_levenshtein(a, b);
+    })
+}
+
+#[bench]
+fn bench_osa_distance(bencher: &mut Bencher) {
+    let a = "Philosopher Friedrich Nietzsche";
+    let b = "Philosopher Jean-Paul Sartre";
+    bencher.iter(|| {
+        strsim::osa_distance(a, b);
+    })
+}
+
+#[bench]
+fn bench_damerau_levenshtein(bencher: &mut Bencher) {
+    let a = "Philosopher Friedrich Nietzsche";
+    let b = "Philosopher Jean-Paul Sartre";
+    bencher.iter(|| {
+        strsim::damerau_levenshtein(a, b);
+    })
+}
+
+#[bench]
+fn bench_normalized_damerau_levenshtein(bencher: &mut Bencher) {
+    let a = "Philosopher Friedrich Nietzsche";
+    let b = "Philosopher Jean-Paul Sartre";
+    bencher.iter(|| {
+        strsim::normalized_damerau_levenshtein(a, b);
+    })
+}
+
+#[bench]
+fn bench_sorensen_dice(bencher: &mut Bencher) {
+    let a = "Philosopher Friedrich Nietzsche";
+    let b = "Philosopher Jean-Paul Sartre";
+    bencher.iter(|| {
+        strsim::sorensen_dice(a, b);
+    })
+}