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

@@ -36,0 +38,4 @@
+                <FieldBytesSize<Self> as ModulusSize>::CompressedPointSize,
+            >,
+        > + ToSec1Point<Self>,
+    // Bounds required by voprf::CipherSuite

@@ -98,1 +106,3 @@
-        > + ToEncodedPoint<G>,
+            Repr = hybrid_array::Array<u8, <FieldBytesSize<G> as ModulusSize>::CompressedPointSize>,
+        > + ToSec1Point<G>,
+    <G as voprf::Group>::SecurityLevel: Mul<U2>,

@@ -183,3 +192,3 @@
     where
         H: BlockSizeUser + Default + FixedOutput + HashMarker,
-        H::OutputSize: IsLess<U256> + IsLessOrEqual<H::BlockSize>,
+        H::OutputSize: IsLess<U256>

@@ -413,3 +422,3 @@
 
     fn serialize(&self) -> GenericArray<u8, Self::Len> {
-        self.client_e_sk.serialize().concat(self.client_nonce)
+        let a = self.client_e_sk.serialize();

@@ -518,3 +524,1 @@
-            .concat(self.session_key.clone())
-            .concat(self.verify_state.serialize())
-            .concat(self.expected_mac.clone())
+        Concat::concat(

@@ -585,3 +602,3 @@
 
     fn serialize(&self) -> GenericArray<u8, Self::Len> {
-        SIG::serialize_signature(&self.signature).concat(self.mac.clone())
+        Concat::concat(

@@ -256,3 +258,2 @@
     {
-        <OprfGroup<CS> as voprf::Group>::serialize_elem(self.evaluation_element.value())
-            .concat(self.server_s_pk.serialize())
+        let elem = GenericArray::from_ha0_4(<OprfGroup<CS> as voprf::Group>::serialize_elem(

@@ -301,3 +305,1 @@
-            .serialize()
-            .concat(self.masking_key.clone())
-            .concat(self.envelope.serialize())
+        Concat::concat(

@@ -343,3 +351,2 @@
     {
-        <OprfGroup<CS> as voprf::Group>::serialize_elem(self.blinded_element.value())
-            .concat(self.ke1_message.serialize())
+        let elem = GenericArray::from_ha0_4(<OprfGroup<CS> as voprf::Group>::serialize_elem(

@@ -402,3 +412,1 @@
-            .concat(self.masking_nonce)
-            .concat(self.masked_response.serialize())
-            .concat(self.ke2_message.serialize())
+        let elem = GenericArray::from_ha0_4(<OprfGroup<CS> as voprf::Group>::serialize_elem(