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/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,