feat(agent): conversation par paire + entrée médiée + pivot terminal/MCP

Coeur inter-agents consolidé et surface front réalignée sur la décision
"terminal natif PTY, pas d'UI chat" (Option 1).

Domaine
- nouveaux modules conversation, mailbox, input, fileguard (ports + types)
- orchestrator/profile/events étendus (conversation par paire, FIFO)

Application / Infrastructure
- orchestrator/service + context_guard : sérialisation FIFO par agent,
  garde RW mémoire/contexte, dispatch ask/reply
- adapters in-memory conversation / mailbox / input / fileguard
- registry session + lifecycle agent durcis (1 agent = 1 session vivante)
- outils MCP idea_* alignés sur le nouveau dispatch

Frontend
- MediatedInput + useAgentBusy : entrée utilisateur médiée par IdeA,
  terminal = vue sortie inchangée
- suppression de la vue chat structurée (AgentChatView) — abandonnée
- adapter input + ports mis à jour

Divers
- .ideai/ : mémoire projet + briefs de cadrage versionnés ;
  requests/ runtime ignoré ; agents projet réels (DevBackend/DevFrontend/QA)

Tests : Rust (domain/application/infrastructure/app-tauri) + front (346) verts.

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

crates/app-tauri/src/commands.rs

@@ -40,7 +40,8 @@ use crate::dto::{
     EmbedderProfileListDto, ErrorDto, FirstRunStateDto, GitBranchesDto, GitCheckoutRequestDto,
     GitCommitDto, GitCommitListDto, GitCommitRequestDto, GitStageRequestDto, GitStatusListDto,
     GraphCommitListDto, HealthRequestDto, HealthResponseDto, InspectConversationRequestDto,
-    LaunchAgentRequestDto, LayoutDto, LayoutOperationDto, ListLayoutsDto, LiveAgentListDto,
+    InterruptAgentRequestDto, LaunchAgentRequestDto, LayoutDto, LayoutOperationDto, ListLayoutsDto,
+    LiveAgentListDto, SubmitAgentInputRequestDto,
     MemoryDto, MemoryIndexDto, MemoryLinksDto, MemoryListDto, OpenTerminalRequestDto, ProfileDto,
     ProfileListDto, ProjectDto, ProjectListDto, ReadAgentContextResponseDto, ReattachChatDto,
     ReattachResultDto, RecallMemoryRequestDto, RenameLayoutRequestDto, ReplyChunk,
@@ -1037,8 +1038,10 @@ pub async fn launch_agent(
     // M5c handshake guard (`serve_peer`) compares against; the `--requester` is the
     // launching agent's id. A missing executable path (should not happen) degrades
     // to no runtime ⇒ apply_mcp_config writes the minimal declaration.
-    let mcp_runtime = std::env::current_exe().ok().map(|exe| McpRuntime {
-        exe: exe.to_string_lossy().into_owned(),
+    // L'exe vient de `idea_exe_path()` (privilégie `$APPIMAGE`, sinon `current_exe`)
+    // pour que chemin GUI et chemin `ask` écrivent un `command` identique et stable.
+    let mcp_runtime = crate::mcp_endpoint::idea_exe_path().map(|exe| McpRuntime {
+        exe,
         endpoint: crate::mcp_endpoint::mcp_endpoint(&project.id)
             .as_cli_arg()
             .to_owned(),
@@ -1203,6 +1206,55 @@ pub async fn agent_send(
     Ok(())
 }
 
+/// `submit_agent_input` — the human **Envoyer** path (cadrage C4 §4.2).
+///
+/// Routes the operator's text to [`OrchestratorService::submit_human_input`], which
+/// enqueues a `from_human` ticket in the **same FIFO** the inter-agent delegations
+/// use (serialised per agent). Fire-and-forget: the human watches the terminal for
+/// the answer. The mediator emits `AgentBusyChanged` at the source.
+///
+/// # Errors
+/// Returns an [`ErrorDto`] (`INVALID` for a malformed id or unwired mediator,
+/// `NOT_FOUND` if the project or agent is unknown, `PROCESS` on a launch/PTY failure).
+#[tauri::command]
+pub async fn submit_agent_input(
+    request: SubmitAgentInputRequestDto,
+    state: State<'_, AppState>,
+) -> Result<(), ErrorDto> {
+    let project = resolve_project(&request.project_id, &state).await?;
+    let agent_id = parse_agent_id(&request.agent_id)?;
+    state
+        .orchestrator_service
+        .submit_human_input(&project, agent_id, request.text)
+        .await
+        .map(|_| ())
+        .map_err(ErrorDto::from)
+}
+
+/// `interrupt_agent` — the **Interrompre** path (cadrage C4 §4.2).
+///
+/// Routes to [`OrchestratorService::interrupt_agent`], which `preempt`s the agent's
+/// running turn (best-effort interrupt to its PTY). Not an enqueue; resolves no
+/// ticket. Idempotent on an idle agent.
+///
+/// # Errors
+/// Returns an [`ErrorDto`] (`INVALID` for a malformed id or unwired mediator,
+/// `NOT_FOUND` if the project or agent is unknown).
+#[tauri::command]
+pub async fn interrupt_agent(
+    request: InterruptAgentRequestDto,
+    state: State<'_, AppState>,
+) -> Result<(), ErrorDto> {
+    let project = resolve_project(&request.project_id, &state).await?;
+    let agent_id = parse_agent_id(&request.agent_id)?;
+    state
+        .orchestrator_service
+        .interrupt_agent(&project, agent_id)
+        .await
+        .map(|_| ())
+        .map_err(ErrorDto::from)
+}
+
 /// `reattach_agent_chat` — re-bind a view to a **still-living** structured session
 /// without re-sending or re-spawning it (ARCHITECTURE §17.6/§17.7).
 ///