feat(agent): UI hot-swap de profil (A2) — commande Tauri + sélecteur + dialog

- Tauri : commande change_agent_profile + ChangeAgentProfileRequestDto/Dto
  (camelCase, relaunchedSession omis si None), câblage state.rs par composition.
- Front : gateway changeAgentProfile (adapters Tauri+mock), sélecteur de profil
  par agent, dialog de confirmation FR (« Changer le moteur abandonne l'historique
  de conversation… »), refresh sur event agentProfileChanged.

Tests : app-tauri dto 5/5 ; vitest 314/314 (mapping, payload, dialog gating,
libellé FR, refresh). 0 régression.

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

crates/app-tauri/src/commands.rs

@@ -9,8 +9,9 @@ use tauri::State;
 
 use crate::dto::DismissEmbedderSuggestionRequestDto;
 use application::{
-    AppError, AssignSkillToAgentInput, CloseProjectInput, CreateAgentInput, CreateLayoutInput,
-    CreateMemoryInput, CreateSkillInput, DeleteAgentInput, DeleteEmbedderProfileInput,
+    AppError, AssignSkillToAgentInput, ChangeAgentProfileInput, CloseProjectInput, CreateAgentInput,
+    CreateLayoutInput, CreateMemoryInput, CreateSkillInput, DeleteAgentInput,
+    DeleteEmbedderProfileInput,
     DeleteLayoutInput, DeleteMemoryInput, DeleteSkillInput, DeleteTemplateInput,
     DetectAgentDriftInput, GetMemoryInput, GitBranchesInput, GitCheckoutInput, GitCommitInput,
     GitGraphInput, GitInitInput, GitLogInput, GitStagePathInput, GitStatusInput,
@@ -27,7 +28,8 @@ use crate::dto::{
     parse_agent_id, parse_close_terminal, parse_delete_profile, parse_layout_id, parse_memory_slug,
     parse_node_id, parse_profile_id, parse_project_id, parse_session_id, parse_skill_id,
     parse_template_id, AgentDriftListDto, AgentDto, AgentListDto, AssignSkillRequestDto,
-    AttachLiveAgentRequestDto, ConfigureProfilesRequestDto, ConversationDetailsDto,
+    AttachLiveAgentRequestDto, ChangeAgentProfileDto, ChangeAgentProfileRequestDto,
+    ConfigureProfilesRequestDto, ConversationDetailsDto,
     CreateAgentFromTemplateRequestDto, CreateAgentRequestDto, CreateLayoutRequestDto,
     CreateLayoutResultDto, CreateMemoryRequestDto, CreateProjectRequestDto, CreateSkillRequestDto,
     CreateTemplateRequestDto, DeleteLayoutRequestDto, DeleteLayoutResultDto,
@@ -1037,6 +1039,42 @@ pub async fn launch_agent(
     Ok(TerminalSessionDto::from(output))
 }
 
+/// `change_agent_profile` — hot-swap an agent's runtime profile (§15.1).
+///
+/// Mutates the profile in the manifest, clears the now-foreign conversation id on
+/// every persisted layout cell hosting the agent, and — if the agent is live —
+/// kills its PTY and relaunches the session in the same cell with the new engine.
+/// Announces [`DomainEvent::AgentProfileChanged`].
+///
+/// Returns the mutated [`AgentDto`] and the relaunched [`TerminalSessionDto`] when
+/// a live session was hot-swapped (absent otherwise).
+///
+/// # Errors
+/// Returns an [`ErrorDto`] (`INVALID` for malformed ids, `NOT_FOUND` if the
+/// project, agent or target profile is unknown, `STORE`/`FILESYSTEM`/`PROCESS` on
+/// the respective port failures).
+#[tauri::command]
+pub async fn change_agent_profile(
+    request: ChangeAgentProfileRequestDto,
+    state: State<'_, AppState>,
+) -> Result<ChangeAgentProfileDto, ErrorDto> {
+    let project = resolve_project(&request.project_id, &state).await?;
+    let agent_id = parse_agent_id(&request.agent_id)?;
+    let profile_id = parse_profile_id(&request.profile_id)?;
+    state
+        .change_agent_profile
+        .execute(ChangeAgentProfileInput {
+            project,
+            agent_id,
+            profile_id,
+            rows: request.rows,
+            cols: request.cols,
+        })
+        .await
+        .map(ChangeAgentProfileDto::from)
+        .map_err(ErrorDto::from)
+}
+
 // ---------------------------------------------------------------------------
 // Templates & sync (L7)
 // ---------------------------------------------------------------------------

crates/app-tauri/src/dto.rs

@@ -1032,10 +1032,10 @@ pub fn parse_profile_id(raw: &str) -> Result<ProfileId, ErrorDto> {
 // ---------------------------------------------------------------------------
 
 use application::{
-    CreateAgentOutput, InspectConversationOutput, LaunchAgentOutput, ListAgentsOutput,
-    ReadAgentContextOutput,
+    ChangeAgentProfileOutput, CreateAgentOutput, InspectConversationOutput, LaunchAgentOutput,
+    ListAgentsOutput, ReadAgentContextOutput,
 };
-use domain::Agent;
+use domain::{Agent, TerminalSession};
 
 /// An agent crossing the wire. [`Agent`] already serialises camelCase
 /// (`id`, `name`, `contextPath`, `profileId`, `origin` tagged, `synchronized`),
@@ -1154,6 +1154,56 @@ impl From<LaunchAgentOutput> for TerminalSessionDto {
     }
 }
 
+/// Request DTO for `change_agent_profile` (§15.1): hot-swap an agent's runtime
+/// profile, optionally relaunching its live session in place.
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ChangeAgentProfileRequestDto {
+    /// Id of the owning project.
+    pub project_id: String,
+    /// Id of the agent whose runtime profile to change.
+    pub agent_id: String,
+    /// Id of the new runtime profile.
+    pub profile_id: String,
+    /// Terminal height in rows for a possible hot relaunch.
+    pub rows: u16,
+    /// Terminal width in columns for a possible hot relaunch.
+    pub cols: u16,
+}
+
+/// Response DTO for `change_agent_profile`: the mutated agent plus the freshly
+/// relaunched session when a live session was hot-swapped (absent otherwise).
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ChangeAgentProfileDto {
+    /// The agent now carrying the new profile.
+    pub agent: AgentDto,
+    /// The relaunched session, present only when a live session was swapped.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub relaunched_session: Option<TerminalSessionDto>,
+}
+
+impl From<ChangeAgentProfileOutput> for ChangeAgentProfileDto {
+    fn from(out: ChangeAgentProfileOutput) -> Self {
+        Self {
+            agent: AgentDto(out.agent),
+            relaunched_session: out.relaunched.map(TerminalSessionDto::from),
+        }
+    }
+}
+
+impl From<TerminalSession> for TerminalSessionDto {
+    fn from(s: TerminalSession) -> Self {
+        Self {
+            session_id: s.id.to_string(),
+            cwd: s.cwd.as_str().to_owned(),
+            rows: s.pty_size.rows,
+            cols: s.pty_size.cols,
+            assigned_conversation_id: None,
+        }
+    }
+}
+
 /// Request DTO for `inspect_conversation` (T7).
 #[derive(Debug, Clone, Deserialize)]
 #[serde(rename_all = "camelCase")]

crates/app-tauri/src/lib.rs

@@ -126,6 +126,7 @@ pub fn run() {
             commands::update_agent_context,
             commands::delete_agent,
             commands::launch_agent,
+            commands::change_agent_profile,
             commands::inspect_conversation,
             commands::create_template,
             commands::update_template,

crates/app-tauri/src/state.rs

@@ -10,7 +10,8 @@ use std::path::PathBuf;
 use std::sync::{Arc, Mutex};
 
 use application::{
-    AssignSkillToAgent, CheckEmbedderSuggestion, CloseProject, CloseTab, CloseTerminal,
+    AssignSkillToAgent, ChangeAgentProfile, CheckEmbedderSuggestion, CloseProject, CloseTab,
+    CloseTerminal,
     ConfigureProfiles, CreateAgentFromScratch, CreateAgentFromTemplate, CreateLayout, CreateMemory,
     CreateProject, CreateSkill, CreateTemplate, DeleteAgent, DeleteEmbedderProfile, DeleteLayout,
     DeleteMemory, DeleteProfile, DeleteSkill, DeleteTemplate, DescribeEmbedderEngines,
@@ -128,6 +129,8 @@ pub struct AppState {
     pub delete_agent: Arc<DeleteAgent>,
     /// Launch an agent (spawn PTY, apply injection strategy).
     pub launch_agent: Arc<LaunchAgent>,
+    /// Hot-swap an agent's runtime profile, relaunching its live session in place (§15.1).
+    pub change_agent_profile: Arc<ChangeAgentProfile>,
     /// Best-effort inspection of a conversation (last topic + token indicator)
     /// for the resume popup (T7). Optional/extensible: backed by a `Vec` of
     /// [`domain::ports::SessionInspector`]s; an empty/missing match yields empty
@@ -514,6 +517,20 @@ impl AppState {
             Some(Arc::clone(&check_embedder_suggestion)),
         ));
 
+        // Hot-swap an agent's runtime profile (§15.1). Reuses the shared context/
+        // profile/project/fs stores, the live-session registry and PTY port, and
+        // *composes* the launcher above for the in-place relaunch (no duplication).
+        let change_agent_profile = Arc::new(ChangeAgentProfile::new(
+            Arc::clone(&contexts_port),
+            Arc::clone(&profile_store_port),
+            Arc::clone(&store_port),
+            Arc::clone(&fs_port),
+            Arc::clone(&terminal_sessions),
+            Arc::clone(&pty_port),
+            Arc::clone(&launch_agent),
+            Arc::clone(&events_port),
+        ));
+
         // --- Conversation inspection (T7) ---
         // Best-effort, optional, extensible: a `Vec` of SessionInspectors routed
         // by profile. Adding an inspectable CLI = pushing one more adapter here.
@@ -699,6 +716,7 @@ impl AppState {
             update_agent_context,
             delete_agent,
             launch_agent,
+            change_agent_profile,
             inspect_conversation,
             project_store,
             create_template,