feat: toggle to keep model/agent when switching sessions

packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx

@@ -238,6 +238,9 @@ export function Prompt(props: PromptProps) {
 
       syncedSessionID = sessionID
 
+      const shouldSync = kv.get("sync_prompt_context_on_session_switch", true)
+      if (!shouldSync) return
+
       // Only set agent if it's a primary agent (not a subagent)
       const isPrimaryAgent = local.agent.list().some((x) => x.name === msg.agent)
       if (msg.agent && isPrimaryAgent) {

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -165,6 +165,7 @@ export function Session() {
   const [diffWrapMode] = kv.signal<"word" | "none">("diff_wrap_mode", "word")
   const [_animationsEnabled, _setAnimationsEnabled] = kv.signal("animations_enabled", true)
   const [showGenericToolOutput, setShowGenericToolOutput] = kv.signal("generic_tool_output_visibility", false)
+  const [syncPromptContext, setSyncPromptContext] = kv.signal("sync_prompt_context_on_session_switch", true)
 
   const wide = createMemo(() => dimensions().width > 120)
   const sidebarVisible = createMemo(() => {
@@ -682,6 +683,15 @@ export function Session() {
         dialog.clear()
       },
     },
+    {
+      title: syncPromptContext() ? "Keep model/agent when switching sessions" : "Restore model/agent per session",
+      value: "session.toggle.sync_prompt_context",
+      category: "Session",
+      onSelect: (dialog) => {
+        setSyncPromptContext((prev) => !prev)
+        dialog.clear()
+      },
+    },
     {
       title: "Page up",
       value: "session.page.up",
@@ -1064,8 +1074,8 @@ export function Session() {
                 paddingLeft: 1,
                 visible: showScrollbar(),
                 trackOptions: {
-                  backgroundColor: theme.backgroundElement,
-                  foregroundColor: theme.border,
+                  backgroundColor: theme.background,
+                  foregroundColor: theme.borderActive,
                 },
               }}
               stickyScroll={true}