Replace funty dependency with platform-num (Numbers) for LinkType trait

[konard]

Summary

Replace funty::Unsigned and FuntyPart in the LinkType trait definition with LinkReference from platform-num (Numbers), eliminating the funty dependency entirely.

Current state

platform-data 1.0.0 defines LinkType as:

pub trait LinkType:
    Unsigned           // from funty 2.0.0
    + FuntyPart        // local trait wrapping TryFrom<u8>
    + TryFrom<i8, Error: Debug>
    + TryFrom<u8, Error: Debug>
    // ... all integer TryFrom/TryInto bounds
{}

This depends on funty 2.0.0 for the Unsigned trait. Meanwhile, platform-trees uses num_traits::Unsigned (via platform-num::Number), which is a different trait from a different crate. This creates incompatibility at the generic level — you can't write T: data::LinkType + trees::LinkType without dual bounds because neither implies the other.

Proposed change

Once linksplatform/Numbers#144 is implemented (adding TryFrom/TryInto bounds and funty() method to LinkReference), refactor LinkType to:

pub trait LinkType: LinkReference {}

Or simply replace LinkType with LinkReference throughout the crate.

This would:

1. Remove funty from dependencies — Unsigned from num_traits (included in LinkReference via Number) replaces funty::Unsigned
2. Remove FuntyPart trait — the funty() method will be on LinkReference directly
3. Remove all explicit TryFrom/TryInto bounds — they'll be part of LinkReference
4. Unify with platform-trees — both crates will use the same base trait

Impact on downstream crates

• doublets-rs can use a single T: LinkReference bound instead of T: data::LinkType + trees::LinkType
• Any crate depending on platform-data for LinkType would get the same concrete type support

Related

• Add TryFrom/TryInto bounds and FuntyPart-like functionality to LinkReference Numbers#144 — Add required bounds to LinkReference
• linksplatform/trees-rs issue — Corresponding change for trees
• Double check we don't depend on any non stable features of rust and use all the latest best practices and versions of rust in the code doublets-rs#47 — Original issue driving this unification
• Port doublets to stable Rust, migrate deps to crates.io, update CI/CD doublets-rs#48 — PR with full analysis

[konard]

Update from Numbers#144 (platform-num)

LinkReference in platform-num now includes all bounds needed by data::LinkType:

data-rs LinkType requirement	LinkReference status
Unsigned	✅ num_traits::Unsigned (replaces funty::Unsigned)
FuntyPart (TryFrom<u8> + funty method)	✅ Replaced by from_byte(n: u8) -> Self
TryFrom<T> for all integer types	✅ All 12 types with Error: Debug
TryInto<T> for all integer types	✅ All 12 types with Error: Debug

Key decisions

• funty eliminated: num_traits::Unsigned replaces funty::Unsigned. The from_byte(n: u8) method replaces FuntyPart::funty().
• u128 support: LinkReference is now explicitly supported for u8, u16, u32, u64, u128, usize.
• Migration path: Replace T: data::LinkType with T: LinkReference, replace T::funty(n) with T::from_byte(n), and remove the funty dependency.

See: linksplatform/Numbers#145

We need to download all logs and data related about the issue to this repository, make sure we compile that data to ./docs/case-studies/issue-{id} folder, and use it to do deep case study analysis (also make sure to search online for additional facts and data), in which we will reconstruct timeline/sequence of events, list of each and all requirements from the issue, find root causes of the each problem, and propose possible solutions and solution plans for each requirement (we should also check known existing components/libraries, that solve similar problem or can help in solutions).

If there is not enough data to find actual root cause, add debug output and verbose mode if not present, that will allow us to find root cause on next iteration.

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