Rename hardfork-mode to hardfork-handling

The (now-closed) hard fork automation MIP specifies that the name of the
option controlling the feature will be --hardfork-handling, with values
keep-running and migrate-exit.

This is an internal flag; for the upcoming Mesa hard fork, users are
expected to choose the auto hard fork package if they want to use the
"auto" mode. For that reason, the specification in the MIP gave it this
somewhat awkward new name to more accurately reflect what daemon
behaviours will change if it is enabled.

Author: cjjdespres

src/app/cli/src/cli_entrypoint/mina_cli_entrypoint.ml

@@ -610,20 +610,24 @@ let setup_daemon logger ~itn_features ~default_snark_worker_fee =
         "true|false Whether to send the commit SHA used to build the node to \
          the uptime service. (default: false)"
       no_arg
-  and hardfork_mode =
-    (*
-      There's 2 hardfork mode, namely Legacy and Auto. Reference:
-        - https://www.notion.so/o1labs/HF-Mina-node-changes-specification-216e79b1f910805d9865e44f2f4baf0e 
-        - https://www.notion.so/o1labs/V2-MIP-draft-HF-automation-250e79b1f9108010b0c5f2b1f416640b
-        *)
-    flag "--hardfork-mode" ~aliases:[ "hardfork-mode" ]
+  and hardfork_handling =
+    (* The two hard fork modes are migrate-exit (the "auto" hard fork mode) and
+       keep-running (the "legacy" hard fork mode). See
+       https://github.com/MinaProtocol/MIPs/pull/32. This option currently only
+       controls the ledger sync feature (keeping migrated versions of the root
+       and epoch ledger databases alongside the stable ones). TODO: the code
+       will eventually need to be updated so this option also causes the daemon
+       to generate and save its own hard fork config at the [slot_chain_end] and
+       then shut down. *)
+    flag "--hardfork-handling" ~aliases:[ "hardfork-handling" ]
       ~doc:
-        "auto|legacy Mode of hardfork. Under auto mode, the daemon would back \
-         all ledgers that are needed for post-hardfork node to bootstrap with \
-         2 databases, one for before, and one for after the hardfork. Under \
-         legacy mode, all databased backed ledgers are backed by one database. \
-         THIS FLAG IS INTERNAL USE ONLY AND WOULD BE REMOVED WITHOUT NOTICE"
-      (optional_with_default Hardfork_mode.Legacy Hardfork_mode.arg)
+        "keep-running|migrate-exit Internal flag, controlling how the daemon \
+         handles an upcoming hard fork. Exposed for testing purposes. \
+         Currently it only causes the daemon to maintain migrated versions of \
+         the root and epoch ledger databases alongside the stable databases. \
+         (default: keep-running). "
+      (optional_with_default Hardfork_handling.Keep_running
+         Hardfork_handling.arg )
   in
   let to_pubsub_topic_mode_option =
     let open Gossip_net.Libp2p in
@@ -833,7 +837,7 @@ let setup_daemon logger ~itn_features ~default_snark_worker_fee =
           in
           let compile_config = Mina_compile_config.Compiled.t in
           let ledger_backing_type =
-            Mina_lib.Config.ledger_backing ~hardfork_mode
+            Mina_lib.Config.ledger_backing ~hardfork_handling
           in
           let%bind ( precomputed_values
                    , config_jsons
@@ -1472,7 +1476,7 @@ Pass one of -peer, -peer-list-file, -seed, -peer-list-url.|} ;
                  ~node_status_url ~graphql_control_port:itn_graphql_port
                  ~simplified_node_stats
                  ~zkapp_cmd_limit:(ref compile_config.zkapp_cmd_limit)
-                 ~itn_features ~compile_config ~hardfork_mode () )
+                 ~itn_features ~compile_config ~hardfork_handling () )
           in
           { mina
           ; client_trustlist

src/lib/cli_lib/arg_type.ml

@@ -147,16 +147,16 @@ let work_selection_method_to_module :
   | Random_offset ->
       (module Work_selector.Selection_methods.Random_offset)
 
-module Hardfork_mode = struct
-  type t = Auto | Legacy
+module Hardfork_handling = struct
+  type t = Keep_running | Migrate_exit
 
   let of_string = function
-    | "auto" ->
-        Auto
-    | "legacy" ->
-        Legacy
+    | "keep-running" ->
+        Keep_running
+    | "migrate-exit" ->
+        Migrate_exit
     | _ ->
-        failwith "Invalid hardfork mode"
+        failwith "Invalid hardfork handling"
 
   let arg = Command.Arg_type.map Command.Param.string ~f:of_string
 end

src/lib/mina_lib/config.ml

@@ -70,13 +70,13 @@ type t =
   ; zkapp_cmd_limit : int option ref
   ; compile_config : Mina_compile_config.t
   ; itn_features : bool
-  ; hardfork_mode : Cli_lib.Arg_type.Hardfork_mode.t
+  ; hardfork_handling : Cli_lib.Arg_type.Hardfork_handling.t
   }
 [@@deriving make]
 
-let ledger_backing ~hardfork_mode =
-  match hardfork_mode with
-  | Cli_lib.Arg_type.Hardfork_mode.Auto ->
+let ledger_backing ~hardfork_handling =
+  match hardfork_handling with
+  | Cli_lib.Arg_type.Hardfork_handling.Migrate_exit ->
       Root_ledger.Config.Converting_db
-  | _ ->
+  | Cli_lib.Arg_type.Hardfork_handling.Keep_running ->
       Stable_db

src/lib/mina_lib/mina_lib.ml

@@ -2220,7 +2220,7 @@ let create ~commit_id ?wallets (config : Config.t) =
           in
 
           let ledger_backing =
-            Config.ledger_backing ~hardfork_mode:config.hardfork_mode
+            Config.ledger_backing ~hardfork_handling:config.hardfork_handling
           in
           let valid_transitions, initialization_finish_signal =
             Transition_router.run