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/semver-parser/src/version.rs

@@ -0,0 +1,365 @@
+use std::fmt;
+use std::str::from_utf8;
+
+use recognize::*;
+
+use common::{self, numeric_identifier};
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Version {
+    pub major: u64,
+    pub minor: u64,
+    pub patch: u64,
+    pub pre: Vec<Identifier>,
+    pub build: Vec<Identifier>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum Identifier {
+    /// An identifier that's solely numbers.
+    Numeric(u64),
+    /// An identifier with letters and numbers.
+    AlphaNumeric(String),
+}
+
+pub fn parse(version: &str) -> Result<Version, String> {
+    let s = version.trim().as_bytes();
+    let mut i = 0;
+    let major = if let Some((major, len)) = numeric_identifier(&s[i..]) {
+        i += len;
+        major
+    } else {
+        return Err("Error parsing major identifier".to_string());
+    };
+    if let Some(len) = b'.'.p(&s[i..]) {
+        i += len;
+    } else {
+        return Err("Expected dot".to_string());
+    }
+    let minor = if let Some((minor, len)) = numeric_identifier(&s[i..]) {
+        i += len;
+        minor
+    } else {
+        return Err("Error parsing minor identifier".to_string());
+    };
+    if let Some(len) = b'.'.p(&s[i..]) {
+        i += len;
+    } else {
+        return Err("Expected dot".to_string());
+    }
+    let patch = if let Some((patch, len)) = numeric_identifier(&s[i..]) {
+        i += len;
+        patch
+    } else {
+        return Err("Error parsing patch identifier".to_string());
+    };
+    let (pre, pre_len) = common::parse_optional_meta(&s[i..], b'-')?;
+    i += pre_len;
+    let (build, build_len) = common::parse_optional_meta(&s[i..], b'+')?;
+    i += build_len;
+    if i != s.len() {
+        return Err("Extra junk after valid version: ".to_string() +
+            from_utf8(&s[i..]).unwrap());
+    }
+    Ok(Version {
+        major: major,
+        minor: minor,
+        patch: patch,
+        pre: pre,
+        build: build,
+    })
+}
+
+impl fmt::Display for Version {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        try!(write!(f, "{}.{}.{}", self.major, self.minor, self.patch));
+        if !self.pre.is_empty() {
+            let strs: Vec<_> =
+                self.pre.iter().map(ToString::to_string).collect();
+            try!(write!(f, "-{}", strs.join(".")));
+        }
+        if !self.build.is_empty() {
+            let strs: Vec<_> =
+                self.build.iter().map(ToString::to_string).collect();
+            try!(write!(f, "+{}", strs.join(".")));
+        }
+        Ok(())
+    }
+}
+
+impl fmt::Display for Identifier {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Identifier::Numeric(ref id) => id.fmt(f),
+            Identifier::AlphaNumeric(ref id) => id.fmt(f),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use version;
+    use super::*;
+
+    #[test]
+    fn parse_empty() {
+        let version = "";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), "empty string incorrectly considered a valid parse");
+    }
+
+    #[test]
+    fn parse_blank() {
+        let version = "  ";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), "blank string incorrectly considered a valid parse");
+    }
+
+    #[test]
+    fn parse_no_minor_patch() {
+        let version = "1";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), format!("'{}' incorrectly considered a valid parse", version));
+    }
+
+    #[test]
+    fn parse_no_patch() {
+        let version = "1.2";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), format!("'{}' incorrectly considered a valid parse", version));
+    }
+
+    #[test]
+    fn parse_empty_pre() {
+        let version = "1.2.3-";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), format!("'{}' incorrectly considered a valid parse", version));
+    }
+
+    #[test]
+    fn parse_letters() {
+        let version = "a.b.c";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), format!("'{}' incorrectly considered a valid parse", version));
+    }
+
+    #[test]
+    fn parse_with_letters() {
+        let version = "1.2.3 a.b.c";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), format!("'{}' incorrectly considered a valid parse", version));
+    }
+
+    #[test]
+    fn parse_basic_version() {
+        let version = "1.2.3";
+
+        let parsed = version::parse(version).unwrap();
+
+        assert_eq!(1, parsed.major);
+        assert_eq!(2, parsed.minor);
+        assert_eq!(3, parsed.patch);
+    }
+
+    #[test]
+    fn parse_trims_input() {
+        let version = "  1.2.3  ";
+
+        let parsed = version::parse(version).unwrap();
+
+        assert_eq!(1, parsed.major);
+        assert_eq!(2, parsed.minor);
+        assert_eq!(3, parsed.patch);
+    }
+
+    #[test]
+    fn parse_no_major_leading_zeroes() {
+        let version = "01.0.0";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), "01 incorrectly considered a valid major version");
+    }
+
+    #[test]
+    fn parse_no_minor_leading_zeroes() {
+        let version = "0.01.0";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), "01 incorrectly considered a valid minor version");
+    }
+
+    #[test]
+    fn parse_no_patch_leading_zeroes() {
+        let version = "0.0.01";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), "01 incorrectly considered a valid patch version");
+    }
+
+    #[test]
+    fn parse_no_major_overflow() {
+        let version = "98765432109876543210.0.0";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), "98765432109876543210 incorrectly considered a valid major version");
+    }
+
+    #[test]
+    fn parse_no_minor_overflow() {
+        let version = "0.98765432109876543210.0";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), "98765432109876543210 incorrectly considered a valid minor version");
+    }
+
+    #[test]
+    fn parse_no_patch_overflow() {
+        let version = "0.0.98765432109876543210";
+
+        let parsed = version::parse(version);
+
+        assert!(parsed.is_err(), "98765432109876543210 incorrectly considered a valid patch version");
+    }
+
+    #[test]
+    fn parse_basic_prerelease() {
+        let version = "1.2.3-pre";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_pre = vec![Identifier::AlphaNumeric(String::from("pre"))];
+        assert_eq!(expected_pre, parsed.pre);
+    }
+
+    #[test]
+    fn parse_prerelease_alphanumeric() {
+        let version = "1.2.3-alpha1";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_pre = vec![Identifier::AlphaNumeric(String::from("alpha1"))];
+        assert_eq!(expected_pre, parsed.pre);
+    }
+
+    #[test]
+    fn parse_prerelease_zero() {
+        let version = "1.2.3-pre.0";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_pre = vec![Identifier::AlphaNumeric(String::from("pre")),
+                                Identifier::Numeric(0)];
+        assert_eq!(expected_pre, parsed.pre);
+    }
+
+    #[test]
+    fn parse_basic_build() {
+        let version = "1.2.3+build";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_build = vec![Identifier::AlphaNumeric(String::from("build"))];
+        assert_eq!(expected_build, parsed.build);
+    }
+
+    #[test]
+    fn parse_build_alphanumeric() {
+        let version = "1.2.3+build5";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_build = vec![Identifier::AlphaNumeric(String::from("build5"))];
+        assert_eq!(expected_build, parsed.build);
+    }
+
+    #[test]
+    fn parse_pre_and_build() {
+        let version = "1.2.3-alpha1+build5";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_pre = vec![Identifier::AlphaNumeric(String::from("alpha1"))];
+        assert_eq!(expected_pre, parsed.pre);
+
+        let expected_build = vec![Identifier::AlphaNumeric(String::from("build5"))];
+        assert_eq!(expected_build, parsed.build);
+    }
+
+    #[test]
+    fn parse_complex_metadata_01() {
+        let version = "1.2.3-1.alpha1.9+build5.7.3aedf  ";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_pre = vec![Identifier::Numeric(1),
+                                Identifier::AlphaNumeric(String::from("alpha1")),
+                                Identifier::Numeric(9)];
+        assert_eq!(expected_pre, parsed.pre);
+
+        let expected_build = vec![Identifier::AlphaNumeric(String::from("build5")),
+                                  Identifier::Numeric(7),
+                                  Identifier::AlphaNumeric(String::from("3aedf"))];
+        assert_eq!(expected_build, parsed.build);
+    }
+
+    #[test]
+    fn parse_complex_metadata_02() {
+        let version = "0.4.0-beta.1+0851523";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_pre = vec![Identifier::AlphaNumeric(String::from("beta")),
+                                Identifier::Numeric(1)];
+        assert_eq!(expected_pre, parsed.pre);
+
+        let expected_build = vec![Identifier::AlphaNumeric(String::from("0851523"))];
+        assert_eq!(expected_build, parsed.build);
+    }
+
+    #[test]
+    fn parse_metadata_overflow() {
+        let version = "0.4.0-beta.1+98765432109876543210";
+
+        let parsed = version::parse(version).unwrap();
+
+        let expected_pre = vec![Identifier::AlphaNumeric(String::from("beta")),
+                                Identifier::Numeric(1)];
+        assert_eq!(expected_pre, parsed.pre);
+
+        let expected_build = vec![Identifier::AlphaNumeric(String::from("98765432109876543210"))];
+        assert_eq!(expected_build, parsed.build);
+    }
+
+    #[test]
+    fn parse_regression_01() {
+        let version = "0.0.0-WIP";
+
+        let parsed = version::parse(version).unwrap();
+
+        assert_eq!(0, parsed.major);
+        assert_eq!(0, parsed.minor);
+        assert_eq!(0, parsed.patch);
+
+        let expected_pre = vec![Identifier::AlphaNumeric(String::from("WIP"))];
+        assert_eq!(expected_pre, parsed.pre);
+    }
+}