feat(domain,infra,app): rotation/rétention log.jsonl + lecture paginée (LS6)

Backend uniquement (UI React repoussée à LS7) :
- domain : port ConversationArchive + structs SegmentStats/PageCursor/PageDirection/
  TurnSlice/RotationDecision/RotationThresholds, fn pures rotation_plan/clamp_page_limit
  + consts ; re-exports lib.
- infrastructure : impl ConversationArchive pour FsConversationLog (stats/rotate/page
  + helpers), archive segmentée hors chemin chaud.
- application : ReadConversationPage + DTO + ConversationArchiveProvider (conversation/paginate),
  RotateConversationLog (conversation/rotate), exports mod/lib.
- app-tauri : AppConversationArchiveProvider + wiring (state), rotation détachée dans
  launch_agent + commande read_conversation_page (commands), DTOs (dto),
  commande enregistrée (generate_handler!).
- tests (QA, verts) : conversation_log, conversation_rotate_paginate (nouveau),
  dto (module test). Pivots INV-LS6 et cohérence fold-après-rotation verts.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/app-tauri/src/state.rs

@@ -26,14 +26,15 @@ use application::{
     LiveSessions, LiveStateLeanProvider, LiveStateProvider, LiveStateReadProvider, LoadLayout,
     McpRuntime, MoveTabToNewWindow, MutateLayout, OnnxModelView, OpenProject, OpenTerminal,
     OrchestratorService, PermissionProjectorRegistry, ProposeContext, ReadAgentContext,
-    ReadContext, ReadMemory, ReadMemoryIndex, ReadProjectContext, ReadSkill, RecallMemory,
-    ReconcileLayouts, RecordTurn, RecordTurnProvider, ReferenceProfiles, RenameLayout,
-    ResizeTerminal, ResolveAgentPermissions, ResolveMemoryLinks, SaveEmbedderProfile, SaveProfile,
-    SessionLimitService, SetActiveLayout, SnapshotRunningAgents, StopLiveAgent, StructuredSessions,
-    SuggestedThisSession, SyncAgentWithTemplate, TerminalSessions, UnassignSkillFromAgent,
-    UpdateAgentContext, UpdateAgentPermissions, UpdateLiveState, UpdateMemory,
-    UpdateProjectContext, UpdateProjectPermissions, UpdateSkill, UpdateTemplate, WriteMemory,
-    WriteToTerminal, AGENT_MEMORY_RECALL_BUDGET,
+    ReadContext, ReadConversationPage, ReadMemory, ReadMemoryIndex, ReadProjectContext, ReadSkill,
+    RecallMemory, ReconcileLayouts, RecordTurn, RecordTurnProvider, ReferenceProfiles,
+    RenameLayout, ResizeTerminal, ResolveAgentPermissions, ResolveMemoryLinks,
+    RotateConversationLog, SaveEmbedderProfile, SaveProfile, SessionLimitService, SetActiveLayout,
+    SnapshotRunningAgents, StopLiveAgent, StructuredSessions, SuggestedThisSession,
+    SyncAgentWithTemplate, TerminalSessions, UnassignSkillFromAgent, UpdateAgentContext,
+    UpdateAgentPermissions, UpdateLiveState, UpdateMemory, UpdateProjectContext,
+    UpdateProjectPermissions, UpdateSkill, UpdateTemplate, WriteMemory, WriteToTerminal,
+    AGENT_MEMORY_RECALL_BUDGET,
 };
 use domain::ports::{
     AgentContextStore, AgentRuntime, AgentSessionFactory, Clock, Embedder, EmbedderEnvInspector,
@@ -93,6 +94,24 @@ impl RecordTurnProvider for AppRecordTurnProvider {
     }
 }
 
+/// Implémente [`ConversationArchiveProvider`](application::ConversationArchiveProvider)
+/// (lot LS6) en matérialisant un [`FsConversationLog`] (qui implémente aussi
+/// [`domain::ConversationArchive`]) ciblant le **project root** courant.
+///
+/// Même raison d'être que [`AppRecordTurnProvider`] : les use cases d'archivage/pagination
+/// sont uniques pour tous les projets, alors que les logs sont **par project root**. On
+/// construit donc un archive frais par appel, ciblant le bon dossier. Sans état.
+struct AppConversationArchiveProvider;
+
+impl application::ConversationArchiveProvider for AppConversationArchiveProvider {
+    fn conversation_archive_for(
+        &self,
+        root: &domain::project::ProjectPath,
+    ) -> Option<Arc<dyn domain::ConversationArchive>> {
+        Some(Arc::new(FsConversationLog::new(root)) as Arc<dyn domain::ConversationArchive>)
+    }
+}
+
 /// Implémente [`HandoffProvider`](application::HandoffProvider) (lot P7) en
 /// matérialisant un [`FsHandoffStore`] ciblant le **project root** du lancement en
 /// cours.
@@ -414,6 +433,10 @@ pub struct AppState {
     pub list_resumable_agents: Arc<ListResumableAgents>,
     /// Read-only live/busy state for the project's manifest agents.
     pub get_project_work_state: Arc<GetProjectWorkState>,
+    /// Human paginated read of a conversation's full transcript (lot LS6).
+    pub read_conversation_page: Arc<ReadConversationPage>,
+    /// Best-effort log rotation, triggered off the hot path at thread resume/open (lot LS6).
+    pub rotate_conversation_log: Arc<RotateConversationLog>,
     /// Rebinds an already-running agent's live session to a visible cell (Lot D).
     pub attach_live_agent: Arc<AttachLiveAgent>,
     /// Tears down an already-running agent's live session by agent id (Lot D).
@@ -1143,6 +1166,17 @@ impl AppState {
                     as Arc<dyn application::ConversationLogProvider>,
             ),
         );
+        // Lot LS6 — rotation (hors chemin chaud) + lecture humaine paginée. Tous deux
+        // composent le provider d'archive par root ; la rotation lit aussi le handoff
+        // (plancher `up_to`, INV-LS6). Aucune persistance déclenchée par un `append`.
+        let archive_provider = Arc::new(AppConversationArchiveProvider)
+            as Arc<dyn application::ConversationArchiveProvider>;
+        let read_conversation_page =
+            Arc::new(ReadConversationPage::new(Arc::clone(&archive_provider)));
+        let rotate_conversation_log = Arc::new(RotateConversationLog::new(
+            Arc::clone(&archive_provider),
+            Arc::new(AppHandoffProvider) as Arc<dyn application::HandoffProvider>,
+        ));
         // Lot D — actions contrôlées agent-level sur les sessions vivantes : attach
         // (rebind de la cellule-vue, zéro spawn) et stop (kill PTY via la primitive
         // `CloseTerminal` existante / shutdown structuré). Aucune création de session.
@@ -1343,6 +1377,8 @@ impl AppState {
             change_agent_profile,
             list_resumable_agents,
             get_project_work_state,
+            read_conversation_page,
+            rotate_conversation_log,
             attach_live_agent,
             stop_live_agent,
             inspect_conversation,