contributor-rewards, solana-cli, validator-debt: fix the hardcoded 400ms slot times

crates/contributor-rewards/CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- fix(contributor-rewards): resolve the Solana epoch for a timestamp from real block times instead of dividing wall clock by a hardcoded 400ms slot duration. The old estimate drifted about 30k slots per day of lookback and picked the wrong epoch near a boundary, and no fixed constant survives the SIMD-0525 rollout. That epoch selects the leader schedule rewards are computed against, so the search now errors rather than returning a wrong answer: a backfill older than the endpoint's ledger retention fails on the `ingestor::demand` path instead of silently mis-estimating (malbeclabs/infra#2317)
+- fix(contributor-rewards): `snapshot` validates before writing. It warns and continues when the leader schedule cannot be fetched, but every consumer rejects a snapshot without one, so the command exited 0 having written an unusable file under the canonical name and a `snapshot` then `export-shapley` chain failed a step late. Pre-existing, but reachable now that resolving the Solana epoch depends on block-time reads (malbeclabs/infra#2317)
 - migrate to Solana 3.0: workspace `solana-*` crates and `solana-sdk` move to the 3.0 line, `solana-program-test` to 3.0.12, and the doublezero SDK git-deps repin from `client/v0.27.1` to the malbeclabs/doublezero#3830 merge revision (malbeclabs/infra#1853)
 - release artifact now builds as a static `x86_64-unknown-linux-musl` binary (malbeclabs/infra#1853)
 - TLS for HTTP clients moves from openssl to rustls; trust roots are the bundled webpki Mozilla set plus the host OS certificate store, so OS-installed private CAs remain trusted (malbeclabs/infra#1853)

crates/contributor-rewards/src/cli/snapshot.rs

@@ -252,31 +252,22 @@ pub async fn create_snapshot(
         fetcher.dz_rpc_client.clone(),
         fetcher.solana_read_client.clone(),
     );
-    let solana_epoch = match epoch_finder
-        .find_epoch_at_timestamp(fetch_data.start_us)
+    // fetch_leader_schedule resolves the Solana epoch itself and reports which
+    // one it used, so taking the epoch from its result avoids running the
+    // chain-verified epoch search twice over the same timestamp.
+    let leader_schedule = match epoch_finder
+        .fetch_leader_schedule(fetch_epoch, fetch_data.start_us)
         .await
     {
-        Ok(epoch) => Some(epoch),
+        Ok(schedule) => Some(schedule),
         Err(e) => {
-            warn!("Failed to determine Solana epoch: {}", e);
+            warn!("Failed to get leader schedule: {}", e);
             None
         }
     };
-
-    let leader_schedule = if solana_epoch.is_some() {
-        match epoch_finder
-            .fetch_leader_schedule(fetch_epoch, fetch_data.start_us)
-            .await
-        {
-            Ok(schedule) => Some(schedule),
-            Err(e) => {
-                warn!("Failed to get leader schedule: {}", e);
-                None
-            }
-        }
-    } else {
-        None
-    };
+    let solana_epoch = leader_schedule
+        .as_ref()
+        .map(|schedule| schedule.solana_epoch);
 
     // Create metadata
     let metadata = SnapshotMetadata {
@@ -327,6 +318,11 @@ pub async fn create_snapshot(
         Network::Devnet => "dn",
     };
 
+    // Refuse to write a snapshot no consumer can read. Without this the command
+    // exits 0 having left an unusable file under the canonical name, and the
+    // failure surfaces a step later in whatever reads it next.
+    snapshot.validate()?;
+
     // Export: local override or configured storage
     if local_file.is_some() || local_dir.is_some() {
         // Save to local filesystem (ignores storage backend config)