fix(ci): admit intentional async trait implementations

src/pager/core.rs

@@ -389,7 +389,7 @@ impl<V: Vfs> Pager<V> {
         &self.vfs
     }
 
-    #[allow(clippy::unused_async)]
+    #[allow(clippy::unused_async, clippy::unused_async_trait_impl)]
     pub async fn open(vfs: V, mk: MasterKey, cfg: PagerConfig) -> Result<Self> {
         let inner = Arc::new(PagerInner {
             buffer_pool: parking_lot::Mutex::new(PageCache::with_capacity(cfg.buffer_pool_pages)),
@@ -542,7 +542,7 @@ impl<V: Vfs> Pager<V> {
     /// Write (insert into cache as dirty) a main.db page. The copy-on-write caller has
     /// already chosen `page_id`. `body_plain` is the plaintext payload
     /// (length must equal `page_size - 40`).
-    #[allow(clippy::unused_async)]
+    #[allow(clippy::unused_async, clippy::unused_async_trait_impl)]
     pub async fn write_main_page(
         &self,
         page_id: u64,
@@ -567,7 +567,7 @@ impl<V: Vfs> Pager<V> {
     /// page 0 is the segment header, allocated separately by the segment
     /// writer in a later slice). Test-only; see [`Self::read_segment_page`].
     #[cfg(test)]
-    #[allow(clippy::unused_async)]
+    #[allow(clippy::unused_async, clippy::unused_async_trait_impl)]
     pub async fn append_segment_page(
         &self,
         segment_id: [u8; 16],
@@ -610,7 +610,7 @@ impl<V: Vfs> Pager<V> {
     /// native-only (filesystem-backed VFS root); on wasm32 it never compiles
     /// in, leaving this unreachable there.
     #[cfg(not(target_arch = "wasm32"))]
-    #[allow(clippy::unused_async)]
+    #[allow(clippy::unused_async, clippy::unused_async_trait_impl)]
     pub async fn stage_journal_page(
         &self,
         journal_id: [u8; 16],

src/vfs/memory.rs

@@ -106,6 +106,9 @@ pub struct MemFile {
     writable: bool,
 }
 
+// These methods implement an async storage contract. Some finish immediately
+// in memory, but keeping the trait-shaped futures avoids a backend-specific API.
+#[allow(clippy::unused_async_trait_impl)]
 impl Vfs for MemVfs {
     type File = MemFile;
     type LockHandle = MemLockHandle;
@@ -221,6 +224,7 @@ impl Vfs for MemVfs {
     }
 }
 
+#[allow(clippy::unused_async_trait_impl)]
 impl VfsFile for MemFile {
     async fn read_at(&self, offset: u64, buf: &mut [u8]) -> Result<usize> {
         let inode = self.inode.lock();

src/vfs/opfs/mod.rs

@@ -81,6 +81,9 @@ mod shim {
 
     pub struct OpfsFileShim;
 
+    // The native shim preserves the async VFS surface while refusing every
+    // operation immediately.
+    #[allow(clippy::unused_async_trait_impl)]
     impl VfsFile for OpfsFileShim {
         async fn read_at(&self, _offset: u64, _buf: &mut [u8]) -> Result<usize> {
             Err(PagedbError::Unsupported)
@@ -114,6 +117,7 @@ mod shim {
     /// Unreachable lock handle for the native shim.
     pub struct OpfsLockHandleShim(());
 
+    #[allow(clippy::unused_async_trait_impl)]
     impl Vfs for OpfsVfs {
         type File = OpfsFileShim;
         type LockHandle = OpfsLockHandleShim;

src/vfs/traits.rs

@@ -596,6 +596,8 @@ mod tests {
         }
     }
 
+    // This synchronous test double implements the production async contract.
+    #[allow(clippy::unused_async_trait_impl)]
     impl VfsFile for ScriptedWriteFile {
         async fn read_at(&self, _offset: u64, _buf: &mut [u8]) -> crate::Result<usize> {
             unimplemented!("read_at is not used by write_all_at tests")

src/vfs/wasi.rs

@@ -459,6 +459,9 @@ mod shim {
 
     pub struct WasiFileShim;
 
+    // The non-WASI shim preserves the async VFS surface while refusing every
+    // operation immediately.
+    #[allow(clippy::unused_async_trait_impl)]
     impl VfsFile for WasiFileShim {
         async fn read_at(&self, _offset: u64, _buf: &mut [u8]) -> Result<usize> {
             Err(PagedbError::Unsupported)
@@ -492,6 +495,7 @@ mod shim {
     /// Unreachable lock handle for the non-WASI shim.
     pub struct WasiLockHandleShim(());
 
+    #[allow(clippy::unused_async_trait_impl)]
     impl Vfs for WasiVfs {
         type File = WasiFileShim;
         type LockHandle = WasiLockHandleShim;