fix(docs): drop stale persist field from projection type-equiv block

ProjectionDefinition lost its persist?: boolean opt-in when every
projection unit became uniformly checkpointed, but the subsystem doc's
type-equiv paste still carried the field, so verify-type-equiv drifted
from packages/session/session-projection/src/index.ts. Remove the field
and its JSDoc from both language sides and re-record the bilingual
pairing record.

docs/subsystems/session-projection.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/subsystems/session-projection.md
-session-projection.md: 50ddc8ddb80a2df1a1c8f54133da134f571ef1ce
-session-projection.zh.md: 06b9f71c263805572ef408d04f9c43021dc13597
+session-projection.md: 2ba14c0ea12a88ae356fb99aabbe72516e0a6602
+session-projection.zh.md: 3defe8fa174647160e9a2b5da7732050e34afe47

docs/subsystems/session-projection.md

@@ -27,8 +27,6 @@ interface ProjectionDefinition<
   key: K
   /** Validates persisted state before it seeds a fold. */
   stateSchema: ZodType<S>
-  /** Persist a host-only unit. Client-visible units are always persisted. */
-  persist?: boolean
   /**
    * State for the empty log.
    * @returns the initial state.

docs/subsystems/session-projection.zh.md

@@ -27,8 +27,6 @@ interface ProjectionDefinition<
   key: K
   /** Validates persisted state before it seeds a fold. */
   stateSchema: ZodType<S>
-  /** Persist a host-only unit. Client-visible units are always persisted. */
-  persist?: boolean
   /**
    * State for the empty log.
    * @returns the initial state.