- Peripheral::read/send now return `expected<unique_ptr<Frame>, Error>`
for a unified success/error interface.
- Peripheral::route returns `expected<unique_ptr<Frame>, Error>` to
distinguish intent: (intentional) non-response vs unable to respond
- Other functions with optional message semantics (handle,poll,react)
return a unique_ptr whose ownership-state indicates response intent
(i.e. send new message)
Bundled necessary changes:
- Switch Frame allocation from global to local (enabled via member
function new/delete)
- Add new header-library tl::expected to shim avr-libstdcpp
Unrelated: Defensive `continue` added after `route`, to reduce Bus
activity check latency
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Some knock-on changes to keep a simple design:
- Bake the data array into AVCLAN_frame_t
- Bundle the response/reaction with AVCLAN_frame_t
- (Needed to maintain correct/simple ownership semantics with the
cache and outgoing/incoming queues)
- Switch status frame update ticks to use a regular
cache-originating/owned frame
Allen Hill