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/pulldown-cmark/tests/suite/strikethrough.rs

@@ -0,0 +1,164 @@
+// This file is auto-generated by the build script
+// Please, do not modify it manually
+
+use super::test_markdown_html;
+
+#[test]
+fn strikethrough_test_1() {
+    let original = r##"~~This is *stricken out*~~
+"##;
+    let expected = r##"<p><del>This is <em>stricken out</em></del></p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_2() {
+    let original = r##"~~This is \~\~stricken~~
+"##;
+    let expected = r##"<p><del>This is ~~stricken</del></p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_3() {
+    let original = r##"This~~is~~stricken
+"##;
+    let expected = r##"<p>This<del>is</del>stricken</p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_4() {
+    let original = r##"~~This~~is~~stricken~~
+"##;
+    let expected = r##"<p><del>This</del>is<del>stricken</del></p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_5() {
+    let original = r##"Here I strike out an exclamation point~~!~~.
+"##;
+    let expected = r##"<p>Here I strike out an exclamation point<del>!</del>.</p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_6() {
+    let original = r##"~This is stricken out~
+"##;
+    let expected = r##"<p><del>This is stricken out</del></p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_7() {
+    let original = r##"~This is \~stricken~
+"##;
+    let expected = r##"<p><del>This is ~stricken</del></p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_8() {
+    let original = r##"This~is~nothing
+"##;
+    let expected = r##"<p>This~is~nothing</p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_9() {
+    let original = r##"~This~is~nothing~
+"##;
+    let expected = r##"<p><del>This~is~nothing</del></p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_10() {
+    let original = r##"Here I fail to strike out an exclamation point~!~.
+"##;
+    let expected = r##"<p>Here I fail to strike out an exclamation point~!~.</p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_11() {
+    let original = r##"Here I fail to strike out a tilde ~~~.
+"##;
+    let expected = r##"<p>Here I fail to strike out a tilde ~~~.</p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_12() {
+    let original = r##"Here I fail to match up ~~tildes~.
+"##;
+    let expected = r##"<p>Here I fail to match up ~~tildes~.</p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_13() {
+    let original = r##"Here I fail to match up ~tildes~~.
+"##;
+    let expected = r##"<p>Here I fail to match up ~tildes~~.</p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_14() {
+    let original = r##"~~This ~is stricken.~~
+"##;
+    let expected = r##"<p><del>This ~is stricken.</del></p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_15() {
+    let original = r##"~This ~~is stricken.~
+"##;
+    let expected = r##"<p><del>This ~~is stricken.</del></p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}
+
+#[test]
+fn strikethrough_test_16() {
+    let original = r##"~This ~~is stricken~ but this is not~~
+"##;
+    let expected = r##"<p><del>This ~~is stricken</del> but this is not~~</p>
+"##;
+
+    test_markdown_html(original, expected, false, false, false);
+}