refactor!: accept flexible arguments across public signatures

[sephynox]

Summary

Many signatures demanded one concrete type (&[u8], &str, Vec<T>, Box<dyn T>), so callers holding an owned value, an array, or a concrete implementor had to convert first. Parameters now take AsRef, Into, IntoIterator, or impl Trait per the house flexible-arguments rule, except where a dyn-compatible trait method or a fixed crypto role requires the concrete type.

Related Issues

None

Changes Made

• Byte and string parameters accept owned or borrowed values
• Collection parameters accept any iterable, not only a Vec
• Builders that stored a trait object now box it internally
• decode accepts any byte source, including a bare &[u8]
• KDF, nonce, and dyn trait inputs keep their concrete types

Testing

• make test-all: passes

Breaking Changes

• Widened trait methods such as ServletRegistry::insert and TrustBuilder::with_chain are generic.
  • Implementors update their signatures, and those traits are no longer dyn-compatible.
• with_sink, with_analyzer, with_rng, and LoggerConfig::new take the value itself.
  • Drop the Arc::new or Box::new wrapper.

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Note

Medium Risk
Widened trait methods are a breaking change for external implementors; runtime logic is largely unchanged, but the breadth of colony/crypto/cluster touchpoints increases regression surface.

Overview
Breaking API ergonomics refactor: parameters across the crate (and tightbeam-derive) now take AsRef, Into, or IntoIterator instead of fixed &[u8], &str, Vec<T>, or caller-supplied Box/Arc wrappers.

Call sites can pass literals, owned buffers, and arrays directly—e.g. cluster registry lookups use type_key("ping") without extra references, gossip helpers accept array slices, and frame with_rng boxes an impl CryptoRngCore internally. Docs show StdoutBackend without Box::new. Fuzz/colony paths gain the same flexibility for IDs, dial addresses, and advertisement type lists.

Trait surface breaks: widened methods on ServletRegistry (hive) and TrustBuilder::with_chain (and similar) are no longer dyn-compatible—custom implementors must match the new generic signatures. wcet! / timing builders pass analyzers without Arc::new where the API now accepts the value directly.

Behavior at boundaries is unchanged aside from internal .into() / .collect(); the diff is mostly signature widening plus test and call-site cleanup.

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