fix(cmux-next): persist first agent chat titles by default

Packages/macOS/CmuxNext/Sources/CmuxNextBridge/AgentTurnStates.swift

@@ -135,6 +135,14 @@ public nonisolated struct AgentTurnStates: Hashable, Sendable {
            !generated(from: summary["harness"] as? String), !generated(from: summary["family"] as? String) {
             return name
         }
+        if !includingPrompt {
+            // acpmux publishes the first prompt as `title` before its title
+            // request completes. Only a source that names a real chat title
+            // may feed durable workspace auto-naming; an absent source is an
+            // older daemon and is intentionally treated as unknown.
+            let source = summary["titleSource"] as? String
+            guard let source, ["harness", "generated", "adopted"].contains(source) else { return nil }
+        }
         if let title = summary["title"] as? String, !title.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
             return promptGist(title)
         }

Packages/macOS/CmuxNext/Sources/CmuxNextWorkspaceNaming/WorkspaceAutoNameTunables.swift

@@ -1,15 +1,14 @@
 public import CmuxNextDesignTokens
 
-/// The workspace auto-name prototypes (hq#1957; Debug Settings
-/// `workspaces.autoName.variant`, DEV and NIGHTLY only; Release always uses
-/// `live`). One is deleted once Leo picks after dogfood.
+/// The workspace auto-name variants (hq#1957; Debug Settings
+/// `workspaces.autoName.variant`, DEV and NIGHTLY only). Persisted first-chat
+/// titles are the default; live labels remain available for comparison.
 public nonisolated enum WorkspaceAutoNameVariant: String, Sendable, CaseIterable, TunableChoice {
-    /// A: the sidebar row shows the name its front tab gives, and follows that
-    /// tab as it changes; the daemon keeps the default name.
+    /// The sidebar row shows the name its front tab gives, and follows that tab
+    /// as it changes; the daemon keeps the default name.
     case live
-    /// B: as `live`, and the first name the front tab gives is written to the
-    /// daemon once (Rename Workspace's command), so the CLI, window title and
-    /// search see it.
+    /// The first generated chat title is written to the daemon once, so the
+    /// CLI, window title and search see it. Manual and agent renames win.
     case persist
 
     public var tunableTitle: String {
@@ -27,7 +26,7 @@ public nonisolated struct WorkspaceAutoNameTunables {
     public static let variant = Tunable<WorkspaceAutoNameVariant>.choice(
         "workspaces.autoName.variant", .sidebar, "Workspace auto-name",
         help: "How a workspace you never named takes its front tab's name. Applies at once.",
-        default: .live, code: "WorkspaceAutoNameTunables.variant")
+        default: .persist, code: "WorkspaceAutoNameTunables.variant")
 
     public static var all: [TunableDescriptor] { [variant.descriptor] }
 }

Packages/macOS/CmuxNext/Tests/CmuxNextAppTests/AgentTabNamingTests.swift

@@ -49,6 +49,22 @@ struct AgentTabNamingTests {
                 "a name the user gave still wins")
     }
 
+    @Test func generatedTitleDoesNotTreatPromptFallbackAsGenerated() {
+        let prompt = [
+            "sessionId": "p1", "name": "claude-1", "harness": "claude",
+            "title": "Fix the sidebar drag", "titleSource": "prompt",
+        ] as [String: Any]
+        #expect(AgentTurnStates.title(prompt, includingPrompt: false) == nil)
+
+        var generated = prompt
+        generated["titleSource"] = "generated"
+        #expect(AgentTurnStates.title(generated, includingPrompt: false) == "Fix the sidebar drag")
+
+        var renamed = prompt
+        renamed["titleSource"] = "named"
+        #expect(AgentTurnStates.title(renamed, includingPrompt: false) == nil)
+    }
+
     @Test func anUntitledChatReadsAsItsWorkspacesTask() {
         let turns = AgentTurnStateStore()
         let ref = AgentSessionRef(host: Self.chiefHost, session: "c9", harness: "claude")

Packages/macOS/CmuxNext/Tests/CmuxNextWorkspaceNamingTests/WorkspaceAutoNameTests.swift

@@ -9,6 +9,10 @@ struct WorkspaceAutoNameTests {
     private static let live = WorkspaceAutoName(enabled: true, variant: .live)
     private static let persist = WorkspaceAutoName(enabled: true, variant: .persist)
 
+    @Test func theDefaultVariantPersistsTheFirstChatTitle() {
+        #expect(WorkspaceAutoNameTunables.variant.defaultValue == .persist)
+    }
+
     private static func terminal(title: String? = nil, cwd: String? = nil, userName: String? = nil) -> WorkspaceAutoName.Front {
         .terminal(NewWorkspaceName.Tab(kind: .terminal, userName: userName, title: title, pageTitle: nil, url: nil, cwd: cwd))
     }

cmux-tui/crates/acpmux/spec/acpmux-protocol.json

@@ -3372,6 +3372,13 @@
             "null"
           ]
         },
+        "titleSource": {
+          "description": "Who supplied `title`: `prompt` is the first-prompt fallback, while\n`harness`, `generated` and `adopted` are real chat titles. Older peers\nmay omit this field.",
+          "type": [
+            "string",
+            "null"
+          ]
+        },
         "tools": {
           "description": "The chat's tools (`hub/tools.rs`).",
           "items": {

cmux-tui/crates/acpmux/src/hub/views.rs

@@ -289,6 +289,7 @@ impl Hub {
             depth: m.subsession.as_ref().map_or(0, |l| l.depth),
             children: self.subsessions.open_count(&m.id),
             title: m.title.clone(),
+            title_source: m.title_source.clone(),
             last_prompt: m.last_prompt.clone(),
             preview: m.preview.as_deref().map(|p| short_text(p, 160)),
             last_message: last_message(&m),

cmux-tui/crates/acpmux/src/protocol/session.rs

@@ -53,6 +53,12 @@ pub struct SessionSummary {
     /// Its sub-sessions that are not closed.
     pub children: u32,
     pub title: Option<String>,
+    /// Who supplied `title`: `prompt` is the first-prompt fallback, while
+    /// `harness`, `generated` and `adopted` are real chat titles. Older peers
+    /// may omit this field.
+    #[serde(default)]
+    #[schemars(default)]
+    pub title_source: Option<String>,
     pub last_prompt: Option<String>,
     pub preview: Option<String>,
     /// One sidebar line; null before the first prompt.

webviews/src/agent-session/acpmux/protocol/generated/types.ts

@@ -701,6 +701,12 @@ export type SessionSummary = {
   /** Tags that have not expired. */
   tags: Record<string, string>;
   title?: (string | null);
+  /**
+   * Who supplied `title`: `prompt` is the first-prompt fallback, while
+   * `harness`, `generated` and `adopted` are real chat titles. Older peers
+   * may omit this field.
+   */
+  titleSource?: (string | null);
   /** The chat's tools (`hub/tools.rs`). */
   tools: ToolSummary[];
   /** `_acpmux/set_tools` can change them. */