fix(ui): Lot A #151 #158 #159 (QA verte)

- #151: chevauchement des boutons dans la barre supérieure pendant une conversation agent

- #158: popup de reprise de conversation intempestive (ajout cellule / changement layout / projet)

- #159: pastille d'activité de projet

frontend/src/features/layout/LayoutGrid.tsx

@@ -922,6 +922,13 @@ function LeafView({
         if (!conversationId) {
           return doLaunch(opts, onData, undefined);
         }
+        // If the cell was closed/remounted while the agent was running, resume
+        // silently. Layout/project changes must not interrupt an ongoing turn
+        // with a modal choice; the persisted conversation id is the continuity
+        // signal and `agentWasRunning` tells us this was not an intentional stop.
+        if (agentWasRunning) {
+          return doLaunch(opts, onData, conversationId);
+        }
         // Resume case: defer the launch behind the popup. Fetch the best-effort
         // enriched details (last topic + tokens) to enrich it; failure or empty
         // ⇒ degraded mode (status only). Inspection never blocks the resume.
@@ -982,6 +989,7 @@ function LeafView({
         style={{
           position: "absolute",
           top: 2,
+          left: 4,
           // Clear the xterm viewport scrollbar (rendered flush against the right
           // edge, ~15px wide). Without this offset the right-most control — the
           // close button — sits *behind* the scrollbar and is hard to click.
@@ -992,6 +1000,8 @@ function LeafView({
           display: "flex",
           gap: 2,
           alignItems: "center",
+          justifyContent: "flex-end",
+          overflow: "hidden",
         }}
       >
         {/* Agent selector */}
@@ -1053,7 +1063,8 @@ function LeafView({
             border: "1px solid var(--color-border, #3a3a3a)",
             borderRadius: 3,
             padding: "1px 2px",
-            maxWidth: 100,
+            width: 96,
+            minWidth: 56,
           }}
         >
           <option value="">Plain</option>
@@ -1079,6 +1090,7 @@ function LeafView({
               border: "1px solid var(--color-border, #3a3a3a)",
               borderRadius: 3,
               background: "var(--color-surface, #1e1e1e)",
+              maxWidth: 128,
             }}
           >
             <button
@@ -1100,6 +1112,10 @@ function LeafView({
                 fontSize: 11,
                 padding: "1px 6px",
                 cursor: "pointer",
+                maxWidth: 66,
+                overflow: "hidden",
+                textOverflow: "ellipsis",
+                whiteSpace: "nowrap",
               }}
             >
               TUI native
@@ -1122,6 +1138,10 @@ function LeafView({
                 fontSize: 11,
                 padding: "1px 6px",
                 cursor: "pointer",
+                maxWidth: 70,
+                overflow: "hidden",
+                textOverflow: "ellipsis",
+                whiteSpace: "nowrap",
               }}
             >
               CLI custom