fix: opt-in recovery for stalled WAL merges with progress deadlines

.github/workflows/rust-test.yml

@@ -81,7 +81,7 @@ jobs:
       - name: Run etcd-backed HA test suite
         env:
           ETCD_TEST_ENDPOINTS: http://127.0.0.1:2379
-        run: cargo test -p lance-context-master --lib -- --ignored
+        run: cargo test -p lance-context-master -p lance-context-server -p lance-context-merge -- --ignored
 
   coverage:
     runs-on: ubuntu-24.04
@@ -131,7 +131,7 @@ jobs:
           ETCD_TEST_ENDPOINTS: http://127.0.0.1:2379
         run: |
           cargo llvm-cov --no-report --all-features \
-            -p lance-context-master --lib -- --ignored
+            -p lance-context-master -p lance-context-server -p lance-context-merge -- --ignored
       - name: Merge coverage reports
         run: cargo llvm-cov report --lcov --output-path lcov.info
       - name: Upload coverage to Codecov

Cargo.toml

@@ -1,5 +1,6 @@
 [workspace]
 members = [
+    "crates/lance-context-merge",
     "crates/lance-context-core",
     "crates/lance-context-metrics",
     "crates/lance-context",

crates/lance-context-core/Cargo.toml

@@ -18,6 +18,10 @@ default = ["metrics"]
 metrics = ["dep:metrics"]
 
 [dependencies]
+async-trait = "0.1"
+lance-table = "9.0.0"
+lance-io = "9.0.0"
+object_store = "0.13.2"
 base64 = "0.22"
 arrow-array = "58"
 arrow-ipc = "58"

crates/lance-context-core/src/generic_store.rs

@@ -406,6 +406,11 @@ impl GenericStore {
         self.base.prepare_count_merge().await
     }
 
+    /// Check the configured count trigger using only this shard's manifest.
+    pub async fn count_merge_due(&self) -> LanceResult<bool> {
+        self.base.count_merge_due().await
+    }
+
     /// The shared-lock half of [`Self::cleanup_wal`]: seal, then read a
     /// budgeted prefix of flushed generations into memory. Callers holding a
     /// read lock run this while appends continue, then take the write lock

crates/lance-context-core/src/lib.rs

@@ -11,6 +11,7 @@ pub mod generic_codec;
 mod generic_store;
 mod id;
 pub mod merge_budget;
+pub mod merge_write_scope;
 pub mod metrics;
 mod namespace;
 mod record;