cardano-testnet | Extract EpochStateView into its own module

cardano-testnet/cardano-testnet.cabal

@@ -111,6 +111,7 @@ library
                         Parsers.Run
                         Testnet.Blockfrost
                         Testnet.Components.Configuration
+                        Testnet.Components.EpochStateView
                         Testnet.Components.Query
                         Testnet.Defaults
                         Testnet.EpochStateProcessing

cardano-testnet/changelog.d/20260416_124922_mgalazyn_refactor_retry_functions.md

@@ -0,0 +1,13 @@
+### Maintenance
+
+- Unified retry/wait functions in `Testnet.Components.Query` by factoring out a common `retryUntilRightM` core.
+  `retryUntilJustM` and `retryUntilM` are now thin wrappers over this shared primitive, eliminating duplicated timeout/polling logic.
+- Removed `watchEpochStateUpdate` and migrated all call sites to `retryUntilJustM`/`retryUntilM`.
+- Simplified `waitForBlocks` (dropped `MonadCatch` constraint, eliminated `EpochInterval maxBound` hack).
+  Now mirrors `waitForEpochs`: relies solely on the shared retry loop's timeout instead of an outer block-count predicate, avoiding the drift between two independent snapshots of the starting block number.
+- Simplified `checkDRepState` by replacing direct `foldEpochState` usage with `EpochStateView` polling.
+- Simplified `assertNewEpochState` by replacing `watchEpochStateUpdate` with `retryUntilRightM`.
+- Removed unused `nodeConfigPath` and `socketPath` fields from `EpochStateView`.
+- Added `maybeExtractGovernanceActionExpiry` in `Testnet.EpochStateProcessing`, which reads a proposal's `gasExpiresAfter` epoch from the gov state.
+- Rewrote the `Gov Action Timeout` integration test to derive its wait target from the proposal's actual expiry epoch, removing the race window caused by not knowing which epoch the proposal was recorded in.
+  The check now waits one full epoch past the removal boundary so the RATIFY-produced state is @k@-deep stable and cannot be invalidated by a chain rollback.

cardano-testnet/changelog.d/20260416_160000_mgalazyn_stm_epoch_state_view.md

@@ -0,0 +1,4 @@
+### Maintenance
+
+- Retries in `EpochStateView` wake immediately on each epoch state update instead of polling.
+  Multiple threads waiting on the same view wake up together.

cardano-testnet/changelog.d/20260423_120000_jordan.millar_extract_epoch_state_view_module.md

@@ -0,0 +1,7 @@
+### Maintenance
+
+- Extracted `EpochStateView` and its retry loops from `Testnet.Components.Query`
+  into a new module `Testnet.Components.EpochStateView` with a haddock overview
+  of how the writer thread, version counter, and STM-based wait primitive fit
+  together. `Testnet.Components.Query` re-exports the public API so existing
+  callers are unaffected.

cardano-testnet/src/Cardano/Testnet.hs

@@ -29,6 +29,7 @@ module Cardano.Testnet (
 
   -- * EpochState processsing helper functions
   maybeExtractGovernanceActionIndex,
+  maybeExtractGovernanceActionExpiry,
 
   -- * Processes
   procChairman,