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/object/tests/read/coff.rs

@@ -0,0 +1,23 @@
+use object::{pe, read, Object, ObjectSection};
+use std::fs;
+use std::path::PathBuf;
+
+#[cfg(feature = "coff")]
+#[test]
+fn coff_extended_relocations() {
+    let path_to_obj: PathBuf = ["testfiles", "coff", "relocs_overflow.o"].iter().collect();
+    let contents = fs::read(path_to_obj).expect("Could not read relocs_overflow.o");
+    let file =
+        read::coff::CoffFile::<_>::parse(&contents[..]).expect("Could not parse relocs_overflow.o");
+    let code_section = file
+        .section_by_name(".text")
+        .expect("Could not find .text section in relocs_overflow.o");
+    match code_section.flags() {
+        object::SectionFlags::Coff { characteristics } => {
+            assert!(characteristics & pe::IMAGE_SCN_LNK_NRELOC_OVFL != 0)
+        }
+        _ => panic!("Invalid section flags flavour."),
+    };
+    let relocations = code_section.relocations().collect::<Vec<_>>();
+    assert_eq!(relocations.len(), 65536);
+}

vendor/object/tests/read/elf.rs

@@ -0,0 +1,47 @@
+#[cfg(feature = "std")]
+use std::path::{Path, PathBuf};
+
+#[cfg(feature = "std")]
+fn get_buildid(path: &Path) -> Result<Option<Vec<u8>>, object::read::Error> {
+    use object::Object;
+    let file = std::fs::File::open(path).unwrap();
+    let reader = object::read::ReadCache::new(file);
+    let object = object::read::File::parse(&reader)?;
+    object
+        .build_id()
+        .map(|option| option.map(ToOwned::to_owned))
+}
+
+#[cfg(feature = "std")]
+#[test]
+/// Regression test: used to attempt to allocate 5644418395173552131 bytes
+fn get_buildid_bad_elf() {
+    let path: PathBuf = [
+        "testfiles",
+        "elf",
+        "yara-fuzzing",
+        "crash-7dc27920ae1cb85333e7f2735a45014488134673",
+    ]
+    .iter()
+    .collect();
+    let _ = get_buildid(&path);
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn get_buildid_less_bad_elf() {
+    let path: PathBuf = [
+        "testfiles",
+        "elf",
+        "yara-fuzzing",
+        "crash-f1fd008da535b110853885221ebfaac3f262a1c1e280f10929f7b353c44996c8",
+    ]
+    .iter()
+    .collect();
+    let buildid = get_buildid(&path).unwrap().unwrap();
+    // ground truth obtained from GNU binutils's readelf
+    assert_eq!(
+        buildid,
+        b"\xf9\xc0\xc6\x05\xd3\x76\xbb\xa5\x7e\x02\xf5\x74\x50\x9d\x16\xcc\xe9\x9c\x1b\xf1"
+    );
+}

vendor/object/tests/read/macho.rs

@@ -0,0 +1,49 @@
+#[cfg(feature = "std")]
+use object::{Object, ObjectSection as _};
+
+// Test that we can read compressed sections in Mach-O files as produced
+// by the Go compiler.
+#[cfg(feature = "std")]
+#[test]
+fn test_go_macho() {
+    let macho_testfiles = std::path::Path::new("testfiles/macho");
+
+    // Section names we expect to find, whether they should be
+    // compressed, and the actual name of the section in the file.
+    const EXPECTED: &[(&str, bool, &str)] = &[
+        (".debug_abbrev", true, "__zdebug_abbrev"),
+        (".debug_gdb_scripts", false, "__debug_gdb_scri"),
+        (".debug_ranges", true, "__zdebug_ranges"),
+        ("__data", false, "__data"),
+    ];
+
+    for file in &["go-aarch64", "go-x86_64"] {
+        let path = macho_testfiles.join(file);
+        let file = std::fs::File::open(path).unwrap();
+        let reader = object::read::ReadCache::new(file);
+        let object = object::read::File::parse(&reader).unwrap();
+        for &(name, compressed, actual_name) in EXPECTED {
+            let section = object.section_by_name(name).unwrap();
+            assert_eq!(section.name(), Ok(actual_name));
+            let compressed_file_range = section.compressed_file_range().unwrap();
+            let size = section.size();
+            if compressed {
+                assert_eq!(
+                    compressed_file_range.format,
+                    object::CompressionFormat::Zlib
+                );
+                assert_eq!(compressed_file_range.compressed_size, size - 12);
+                assert!(
+                    compressed_file_range.uncompressed_size > compressed_file_range.compressed_size,
+                    "decompressed size is greater than compressed size"
+                );
+            } else {
+                assert_eq!(
+                    compressed_file_range.format,
+                    object::CompressionFormat::None
+                );
+                assert_eq!(compressed_file_range.compressed_size, size);
+            }
+        }
+    }
+}

vendor/object/tests/read/mod.rs

@@ -0,0 +1,5 @@
+#![cfg(feature = "read")]
+
+mod coff;
+mod elf;
+mod macho;