Workspace does not compile: two incompatible baofeng RadioIdent types + non-exhaustive RadioVariant match in serial_hardware.rs

[forkwright]

Finding

cargo check --workspace --all-features fails on main (2 errors) in crates/akroasis/src/radio/serial_hardware.rs. This confirms akroasis#262's core claim ("main does not currently build, and nothing noticed") is still true today, independent of the snafu-0.9 migration #262 originally cited (that part is fixed — no snafu errors remain).

Evidence

cargo check --workspace --all-features @ main (8506c10), 2026-07-16, after installing the missing system deps (libudev-dev, protobuf-compiler — also absent from whatever environment last actually compiled this workspace):

error[E0308]: mismatched types
   --> crates/akroasis/src/radio/serial_hardware.rs:125:39
    |
125 |         let config = identify_variant(&ident).map_err(|_| RadioError::WrongBaudRate {
    |                      ---------------- ^^^^^^ expected `syntonia::baofeng::variant::RadioIdent`, found `syntonia::baofeng::ident::RadioIdent`

error[E0004]: non-exhaustive patterns: `_` not covered
   --> crates/akroasis/src/radio/serial_hardware.rs:143:11
    |
143 |     match config.variant {
    |           ^^^^^^^^^^^^^^ pattern `_` not covered

Root cause: crates/syntonia/src/baofeng/ has two different RadioIdent structs:

• ident.rs::RadioIdent { raw_bytes: Vec<u8>, normalized: [u8; 8], firmware_prefix: String } — normalizes 8/12-byte responses and pre-extracts a clean 6-char firmware prefix in from_raw().
• variant.rs::RadioIdent { raw: Vec<u8> } — a separate, simpler struct whose firmware_prefix() lossy-converts the entire raw buffer to a string (no normalization, no prefix extraction), consumed by variant::identify_variant().

serial_hardware.rs:110 builds an ident.rs-flavored RadioIdent (via protocol.identify()) and passes it to variant::identify_variant, which wants its own variant.rs-flavored type — these have not been reconciled since the two modules diverged (see also akroasis#237, duplicate/conflicting magic-byte constants between constants.rs and variant.rs — same module-split root cause).

Separately, variant_from_config at serial_hardware.rs:141-146 matches all 4 current RadioVariant variants but the enum is #[non_exhaustive] and matched from a different crate, so rustc requires a wildcard arm regardless.

Why this matters

This is the exact failure mode akroasis#262 warns about: no CI workflow compiles the workspace, so a break like this lands and stays silent. Because the two RadioIdent types extract the firmware prefix differently (clean 6-char substring vs. lossy-decoding the whole raw buffer), picking the wrong one over the other is not merely a type-plumbing fix — it changes which bytes get matched against UV5R_PREFIXES/BF_F8HP_PREFIXES, i.e. it can affect which physical radio variant gets identified. Radio misidentification corrupts EEPROM writes (already flagged as a live risk in akroasis#238/#225).

Desired correction

Reconcile ident.rs::RadioIdent and variant.rs::RadioIdent into one canonical type (likely ident.rs's, since it already does correct 8/12-byte normalization and prefix extraction) and update variant::identify_variant to consume it, verifying the firmware-prefix matching behavior is unchanged for both magic-byte-set orderings. Add a _ => None (or explicit) wildcard arm to variant_from_config's match per #[non_exhaustive]. This needs the same review as akroasis#237 since both stem from the constants.rs/variant.rs/ident.rs split never being fully unified — worth fixing together.

Done when: cargo check --workspace --all-features succeeds on main, and identify_variant is called with a single canonical RadioIdent type across syntonia and akroasis.