fix(settings): restore flush_memories aux row on pre-v0.12 hosts

Phase B removed the `flushMemories` field from `AuxiliarySettings`,
the `aux("flush_memories")` reader from the YAML parser, and the
"Flush Memories" row from `AuxiliaryTab.tasks` outright. But
`HermesCapabilities.hasFlushMemoriesAux` still claims (with inverse
semantics) that the row should stay visible on pre-v0.12 hosts where
the task is alive. Project CLAUDE.md documents the same contract.

Restored:
- `AuxiliarySettings.flushMemories: AuxiliaryModel` (and `.empty`).
- `aux("flush_memories")` in both YAML readers
  (`HermesConfig+YAML.swift` and the `HermesFileService` mirror).
- `AuxiliaryTab.tasks` appends the Flush Memories row when
  `hasFlushMemoriesAux` is true, mirroring how `curator` is appended
  on the v0.12+ branch.

On v0.12+ hosts the flag is `false` so the field stays `.empty` and
the row is hidden — no behaviour change for current users.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scarf/Packages/ScarfCore/Sources/ScarfCore/Models/HermesConfig.swift

@@ -260,8 +260,11 @@ public struct VoiceSettings: Sendable, Equatable {
 
 /// Per-task auxiliary model overrides.
 ///
-/// `flush_memories` was removed entirely in Hermes v0.12 (the underlying
-/// task no longer exists), so the corresponding field was dropped here.
+/// `flush_memories` was removed in Hermes v0.12 but remains alive on
+/// pre-v0.12 hosts — the field is preserved here so the YAML parser
+/// can round-trip it and `AuxiliaryTab` can render the row when
+/// `HermesCapabilities.hasFlushMemoriesAux` is set. On v0.12+ the
+/// field stays empty and is never surfaced.
 /// `curator` was added in v0.12 — Curator's review fork uses its own
 /// model so users can keep main-model spend separate from background
 /// maintenance.
@@ -273,6 +276,8 @@ public struct AuxiliarySettings: Sendable, Equatable {
     public var skillsHub: AuxiliaryModel
     public var approval: AuxiliaryModel
     public var mcp: AuxiliaryModel
+    /// pre-v0.12 only; on v0.12+ this stays `.empty` and the row is hidden.
+    public var flushMemories: AuxiliaryModel
     /// v0.12+; pre-v0.12 Hermes installs ignore this slot.
     public var curator: AuxiliaryModel
 
@@ -285,6 +290,7 @@ public struct AuxiliarySettings: Sendable, Equatable {
         skillsHub: AuxiliaryModel,
         approval: AuxiliaryModel,
         mcp: AuxiliaryModel,
+        flushMemories: AuxiliaryModel,
         curator: AuxiliaryModel
     ) {
         self.vision = vision
@@ -294,6 +300,7 @@ public struct AuxiliarySettings: Sendable, Equatable {
         self.skillsHub = skillsHub
         self.approval = approval
         self.mcp = mcp
+        self.flushMemories = flushMemories
         self.curator = curator
     }
     public nonisolated static let empty = AuxiliarySettings(
@@ -304,6 +311,7 @@ public struct AuxiliarySettings: Sendable, Equatable {
         skillsHub: .empty,
         approval: .empty,
         mcp: .empty,
+        flushMemories: .empty,
         curator: .empty
     )
 }

scarf/Packages/ScarfCore/Sources/ScarfCore/Parsing/HermesConfig+YAML.swift

@@ -122,6 +122,7 @@ public extension HermesConfig {
             skillsHub: aux("skills_hub"),
             approval: aux("approval"),
             mcp: aux("mcp"),
+            flushMemories: aux("flush_memories"),
             curator: aux("curator")
         )
 

scarf/scarf/Core/Services/HermesFileService.swift

@@ -129,6 +129,7 @@ struct HermesFileService: Sendable {
             skillsHub: aux("skills_hub"),
             approval: aux("approval"),
             mcp: aux("mcp"),
+            flushMemories: aux("flush_memories"),
             curator: aux("curator")
         )
 

scarf/scarf/Features/Settings/Views/Tabs/AuxiliaryTab.swift

@@ -10,11 +10,13 @@ import ScarfCore
 /// the gateway routing from that single field; there is no separate
 /// `use_gateway` key to write.
 ///
-/// v0.12 dropped the `flush_memories` aux task (the underlying memory
-/// pipeline was rewritten upstream) and added `curator` (the autonomous
-/// skill-maintenance review fork). The Curator row only appears when
-/// `HermesCapabilities.hasCuratorAux` is set so v0.11 hosts don't see a
-/// row that writes a key Hermes ignores.
+/// v0.12 dropped the `flush_memories` aux task on the server side and
+/// added `curator` (the autonomous skill-maintenance review fork). The
+/// Curator row only appears when `HermesCapabilities.hasCuratorAux` is
+/// set; the Flush Memories row only appears when
+/// `HermesCapabilities.hasFlushMemoriesAux` is set (inverse semantics —
+/// `true` only on pre-v0.12 hosts where the task still exists). v0.11
+/// users keep their edit surface; v0.12 users never see it.
 struct AuxiliaryTab: View {
     @Bindable var viewModel: SettingsViewModel
 
@@ -38,6 +40,9 @@ struct AuxiliaryTab: View {
 
     private var tasks: [(key: String, title: LocalizedStringKey, icon: String)] {
         var t = baseTasks
+        if capabilitiesStore?.capabilities.hasFlushMemoriesAux ?? false {
+            t.append(("flush_memories", "Flush Memories", "trash.slash"))
+        }
         if capabilitiesStore?.capabilities.hasCuratorAux ?? false {
             t.append(("curator", "Curator", "sparkles"))
         }
@@ -110,6 +115,7 @@ struct AuxiliaryTab: View {
         case "skills_hub": return viewModel.config.auxiliary.skillsHub
         case "approval": return viewModel.config.auxiliary.approval
         case "mcp": return viewModel.config.auxiliary.mcp
+        case "flush_memories": return viewModel.config.auxiliary.flushMemories
         case "curator": return viewModel.config.auxiliary.curator
         default: return .empty
         }