serviceability: delete migrate_interfaces processor and instruction

CHANGELOG.md

@@ -17,6 +17,7 @@ All notable changes to this project will be documented in this file.
   - Add forward-compatible `NewInterface` struct in `state/interface.rs` with a `size: u16` + `version: u8` on-disk prefix, V3-shaped body, and `flex_algo_node_segments`. Older readers can use the size prefix to skip past unknown future versions in constant time. Additive only — no callers, processors, or SDKs change in this PR ([#3666](https://github.com/malbeclabs/doublezero/pull/3666))
   - Append `new_interfaces: Vec<NewInterface>` to `Device` after `max_multicast_publishers`, behind a custom `BorshSerialize` that projects the on-disk legacy `interfaces` slot from `new_interfaces` (always `Interface::V2` per #3653) and writes `new_interfaces` at the end of the layout. Legacy accounts with no trailing bytes deserialize cleanly: `Device::try_from` rebuilds `new_interfaces` from the legacy enum vec via per-variant `TryFrom`. Older readers continue to parse the legacy slot at its existing offset; newer readers gain forward-compat via the trailing vec. Mutations now go through `Device::replace_interface` / `push_interface` / `remove_interface` so both vecs stay in sync; `find_interface` returns `&NewInterface` and `find_interface_legacy` is a temporary helper for unrelated callers ([#3665](https://github.com/malbeclabs/doublezero/pull/3665))
   - Migrate serviceability processors (`device/interface/{create,update,activate,delete,reject,remove,unlink}`, `link/{accept,activate,closeaccount,create,delete,update}`, `topology/backfill`) to read and mutate `Device::new_interfaces` directly. `device.interfaces` is no longer touched in `processors/`, and `Device::push_interface` now takes a `NewInterface`. `BackfillTopology` no longer mirrors `flex_algo_node_segments` into the legacy in-memory `interfaces` vec — segments live only in `new_interfaces` and are intentionally dropped on the V2-projected on-disk legacy slot ([#3658](https://github.com/malbeclabs/doublezero/issues/3658))
+  - Delete the `MigrateDeviceInterfaces` processor and integration tests from the serviceability program. `Device::TryFrom<&[u8]>` (#3665) now auto-promotes legacy `interfaces` into `new_interfaces` when the trailing vec is missing, and the next account write persists the promoted vec — no standalone migration step is needed. Variant 111 is retained as a `Deprecated111()` tombstone (no-op dispatch, slot reserved so it isn't reused) for compatibility with older clients still emitting the old discriminator ([#3662](https://github.com/malbeclabs/doublezero/issues/3662))
 
 ## [v0.21.0](https://github.com/malbeclabs/doublezero/compare/client/v0.20.0...client/v0.21.0) - 2026-05-01
 

smartcontract/programs/doublezero-serviceability/src/entrypoint.rs

@@ -32,7 +32,6 @@ use crate::{
                 reject::process_reject_device_interface, remove::process_remove_device_interface,
                 unlink::process_unlink_device_interface, update::process_update_device_interface,
             },
-            migrate_interfaces::process_migrate_device_interfaces,
             reject::process_reject_device,
             sethealth::process_set_health_device,
             update::process_update_device,
@@ -448,9 +447,7 @@ pub fn process_instruction(
         DoubleZeroInstruction::BackfillTopology(value) => {
             process_topology_backfill(program_id, accounts, &value)?
         }
-        DoubleZeroInstruction::MigrateDeviceInterfaces(value) => {
-            process_migrate_device_interfaces(program_id, accounts, &value)?
-        }
+        DoubleZeroInstruction::Deprecated111() => (),
     };
     Ok(())
 }

smartcontract/programs/doublezero-serviceability/src/instructions.rs

@@ -22,7 +22,6 @@ use crate::processors::{
             remove::DeviceInterfaceRemoveArgs, unlink::DeviceInterfaceUnlinkArgs,
             update::DeviceInterfaceUpdateArgs,
         },
-        migrate_interfaces::MigrateDeviceInterfacesArgs,
         reject::DeviceRejectArgs,
         sethealth::DeviceSetHealthArgs,
         update::DeviceUpdateArgs,
@@ -235,7 +234,7 @@ pub enum DoubleZeroInstruction {
     ClearTopology(TopologyClearArgs),       // variant 109
     BackfillTopology(TopologyBackfillArgs), // variant 110
 
-    MigrateDeviceInterfaces(MigrateDeviceInterfacesArgs), // variant 111
+    Deprecated111(), // variant 111, (was MigrateDeviceInterfaces)
 }
 
 impl DoubleZeroInstruction {
@@ -376,7 +375,7 @@ impl DoubleZeroInstruction {
             108 => Ok(Self::DeleteTopology(TopologyDeleteArgs::try_from(rest).unwrap())),
             109 => Ok(Self::ClearTopology(TopologyClearArgs::try_from(rest).unwrap())),
             110 => Ok(Self::BackfillTopology(TopologyBackfillArgs::try_from(rest).unwrap())),
-            111 => Ok(Self::MigrateDeviceInterfaces(MigrateDeviceInterfacesArgs::try_from(rest).unwrap())),
+            111 => Ok(Self::Deprecated111()),
 
             _ => Err(ProgramError::InvalidInstructionData),
         }
@@ -520,7 +519,7 @@ impl DoubleZeroInstruction {
             Self::DeleteTopology(_) => "DeleteTopology".to_string(), // variant 108
             Self::ClearTopology(_) => "ClearTopology".to_string(),   // variant 109
             Self::BackfillTopology(_) => "BackfillTopology".to_string(), // variant 110
-            Self::MigrateDeviceInterfaces(_) => "MigrateDeviceInterfaces".to_string(), // variant 111
+            Self::Deprecated111() => "Deprecated111".to_string(),    // variant 111
         }
     }
 
@@ -656,7 +655,7 @@ impl DoubleZeroInstruction {
             Self::DeleteTopology(args) => format!("{args:?}"), // variant 108
             Self::ClearTopology(args) => format!("{args:?}"),  // variant 109
             Self::BackfillTopology(args) => format!("{args:?}"), // variant 110
-            Self::MigrateDeviceInterfaces(args) => format!("{args:?}"), // variant 111
+            Self::Deprecated111() => String::new(),            // variant 111
         }
     }
 }

smartcontract/programs/doublezero-serviceability/src/processors/device/mod.rs

@@ -3,7 +3,6 @@ pub mod closeaccount;
 pub mod create;
 pub mod delete;
 pub mod interface;
-pub mod migrate_interfaces;
 pub mod reject;
 pub mod sethealth;
 pub mod update;