fix: raise MSRV to 1.82 (required by deps) and fix lint suppression

MSRV 1.80 was too optimistic - our dependencies require:
- [email protected] requires rustc 1.82
- [email protected] requires rustc 1.81
- [email protected] requires rustc 1.82
- [email protected] requires rustc 1.81

Also moved #[allow(unused_assignments)] to field level since struct-level
wasn't propagating to fields in derive macro expansion.

Author: 27Bslash6

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
         # Full OS matrix for stable only; MSRV and beta on ubuntu only
         include:
           # MSRV - ensures we don't use newer Rust features
-          - rust: "1.80"
+          - rust: "1.82"
             os: ubuntu-latest
           # Stable - primary target, all platforms
           - rust: stable
@@ -51,7 +51,7 @@ jobs:
         run: cargo fmt --check
 
       - name: Run clippy
-        if: matrix.rust != '1.80'
+        if: matrix.rust != '1.82'
         run: cargo clippy --all-features -- -D warnings
 
       - name: Run tests (all features)

Cargo.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 edition = "2021"
 authors = ["cachekit Contributors"]
 description = "LZ4 compression, xxHash3 integrity, AES-256-GCM encryption for byte payloads"
-rust-version = "1.80"
+rust-version = "1.82"
 license = "MIT"
 repository = "https://github.com/cachekit-io/cachekit-core"
 homepage = "https://github.com/cachekit-io/cachekit-core"

src/encryption/key_derivation.rs

@@ -162,6 +162,7 @@ pub struct TenantKeys {
     pub authentication_key: [u8; 32],
     pub cache_key_salt: [u8; 32],
     #[zeroize(skip)]
+    #[allow(unused_assignments)] // False positive: field IS read, Zeroize derive triggers lint
     pub tenant_id: String,
 }
 

src/encryption/key_rotation.rs

@@ -125,6 +125,7 @@ pub struct KeyRotationState {
     pub new_key: [u8; 32],
     /// Indicates if rotation is currently active (old_key exists)
     #[zeroize(skip)]
+    #[allow(unused_assignments)] // False positive: field IS read, Zeroize derive triggers lint
     pub rotation_active: bool,
 }