* Ogg: include recovered tail packets in Opus duration
Keep the existing missing-granule recovery cursor in step with the packet ends it assigns. Add a regression for a partially and entirely unanchored stream; existing valid end-trimming coverage remains unchanged.
Validation: rustc --edition=2024 --test crates/ogg/src/lib.rs: all 12 tests pass. Scoped rustfmt check passes. Full cargo --offline xtask ci is blocked before build by the uncached pinned egui checkout.
* Ogg: record recovery duration correction