feat: upgrade crypto ecosystem to latest RustCrypto stack

Upgrade all core cryptographic dependencies to their latest versions:

Dependencies:
- digest: 0.10 to 0.11
- elliptic-curve: 0.13 to 0.14
- hkdf: 0.12 to 0.13
- hmac: 0.12 to 0.13
- rand: 0.8 to 0.10
- rand_chacha: 0.3 to 0.10
- sha2: 0.10 to 0.11
- getrandom: 0.2 to 0.4 (WASM)
- ml-kem: 0.3.0-rc.0 to 0.3
- ecdsa: 0.16 to 0.17.0-rc.23
- rfc6979: 0.4 to 0.6 (now internal to ecdsa)
- p256/p384/p521: 0.13 to 0.14.0-rc.15
- curve25519-dalek: 4 to 5.0.0-rc
- ed25519-dalek: 2 to 3.0.0-rc
- cryptoki: 0.9 to 0.12
- rustyline: 17 to 18
- scrypt: 0.11 to 0.12
- voprf replaced by voprf-vx 1.0.0-pre.0

Migration changes:
- generic-array 0.14 to 1.4 with hybrid-array 0.4 interop
- ArrayLength<u8> to ArrayLength (generic-array 1.x)
- Added ConcatExt trait to disambiguate from [T]::concat
- Replaced Hmac with SimpleHmac for digest 0.11 compatibility
- Added OutputSize<H>: ArrayLength bounds throughout Hash trait
- Converted hybrid_array::Array between GenericArray at API boundaries
- Updated GroupEncoding Repr bound to hybrid_array::Array
- ECDSA sign now uses ecdsa::hazmat::sign_prehashed_rfc6979
- Removed direct rfc6979 dependency (handled by ecdsa internally)
- Replaced bincode with postcard for no_std serialization
- Re-exported hybrid_array from crate root

Other changes:
- Renamed crate to opaque-vx
- Increased MSRV to 1.88
- Added cryptography to Cargo.toml categories
- Removed Facebook-specific contributions from CONTRIBUTING.md
- Removed v3 to v4 migration test
- Removed unstable rustfmt configurations for stable compatibility

src/hash.rs

@@ -8,36 +8,45 @@
 
 //! A convenience trait for digest bounds used throughout the library
 
+use digest::block_api::{
+    BlockSizeUser, BufferKindUser, CoreProxy, FixedOutputCore, SmallBlockSizeUser,
+};
 use digest::block_buffer::Eager;
-use digest::core_api::{BlockSizeUser, BufferKindUser, CoreProxy, FixedOutputCore};
-use digest::{FixedOutputReset, HashMarker, OutputSizeUser};
+use digest::{Digest, FixedOutputReset, HashMarker, OutputSizeUser};
 use generic_array::typenum::{IsLess, Le, NonZero, U256};
 
 pub(crate) type OutputSize<H> = <<H as CoreProxy>::Core as OutputSizeUser>::OutputSize;
 
 /// Trait to simplify requirements for [`Hash`].
 pub trait ProxyHash:
-    HashMarker + FixedOutputCore + BufferKindUser<BufferKind = Eager> + Default + Clone
+    HashMarker + FixedOutputCore + BufferKindUser<BufferKind = Eager> + OutputSizeUser + Default + Clone
 where
-    <Self as BlockSizeUser>::BlockSize: IsLess<U256>,
-    Le<<Self as BlockSizeUser>::BlockSize, U256>: NonZero,
+    <Self as SmallBlockSizeUser>::_BlockSize: IsLess<U256>,
+    Le<<Self as SmallBlockSizeUser>::_BlockSize, U256>: NonZero,
 {
 }
 
-impl<T: HashMarker + FixedOutputCore + BufferKindUser<BufferKind = Eager> + Default + Clone>
-    ProxyHash for T
+impl<
+    T: HashMarker
+        + FixedOutputCore
+        + BufferKindUser<BufferKind = Eager>
+        + OutputSizeUser
+        + Default
+        + Clone,
+> ProxyHash for T
 where
-    <Self as BlockSizeUser>::BlockSize: IsLess<U256>,
-    Le<<Self as BlockSizeUser>::BlockSize, U256>: NonZero,
+    <T as SmallBlockSizeUser>::_BlockSize: IsLess<U256>,
+    Le<<T as SmallBlockSizeUser>::_BlockSize, U256>: NonZero,
 {
 }
 
-/// Trait inheriting the requirements from [`digest::Digest`] for compatibility
+/// Trait inheriting the requirements from [`Digest`] for compatibility
 /// with HKDF and HMAC Associated types could be simplified when they are made
 /// as defaults: <https://github.com/rust-lang/rust/issues/29661>
 pub trait Hash:
     Default
     + HashMarker
+    + Digest
     + OutputSizeUser<OutputSize = OutputSize<Self>>
     + BlockSizeUser
     + FixedOutputReset
@@ -45,14 +54,16 @@ pub trait Hash:
     + Clone
 where
     <Self as CoreProxy>::Core: ProxyHash,
-    <<Self as CoreProxy>::Core as BlockSizeUser>::BlockSize: IsLess<U256>,
-    Le<<<Self as CoreProxy>::Core as BlockSizeUser>::BlockSize, U256>: NonZero,
+    <<Self as CoreProxy>::Core as SmallBlockSizeUser>::_BlockSize: IsLess<U256>,
+    Le<<<Self as CoreProxy>::Core as SmallBlockSizeUser>::_BlockSize, U256>: NonZero,
+    OutputSize<Self>: generic_array::ArrayLength,
 {
 }
 
 impl<
     T: Default
         + HashMarker
+        + Digest
         + OutputSizeUser<OutputSize = OutputSize<Self>>
         + BlockSizeUser
         + FixedOutputReset
@@ -60,8 +71,9 @@ impl<
         + Clone,
 > Hash for T
 where
-    <Self as CoreProxy>::Core: ProxyHash,
-    <<Self as CoreProxy>::Core as BlockSizeUser>::BlockSize: IsLess<U256>,
-    Le<<<Self as CoreProxy>::Core as BlockSizeUser>::BlockSize, U256>: NonZero,
+    <T as CoreProxy>::Core: ProxyHash,
+    <<T as CoreProxy>::Core as SmallBlockSizeUser>::_BlockSize: IsLess<U256>,
+    Le<<<T as CoreProxy>::Core as SmallBlockSizeUser>::_BlockSize, U256>: NonZero,
+    OutputSize<T>: generic_array::ArrayLength,
 {
 }