Use one markdown path and coalesce messaging refreshes

packages/HostUI/Sources/HostUI/HostUIMarkdown.swift

@@ -4,17 +4,49 @@ import SwiftUI
 
 /// Shared markdown + `$profile` token coloring for HostUI message bodies.
 public enum HostUIMarkdown {
+    /// Dark green for `$handle` and `[Derrick:handle]`. Darker than system green on white bubbles.
+    public static let profileTokenColor = Color(red: 0.0, green: 0.42, blue: 0.18)
+
     public static func attributed(_ text: String) -> AttributedString {
         var options = AttributedString.MarkdownParsingOptions()
         options.interpretedSyntax = .inlineOnlyPreservingWhitespace
         var attributed = (try? AttributedString(markdown: text, options: options))
             ?? AttributedString(text)
-        for range in AgentProfileTokenHighlight.ranges(in: text) {
-            let snippet = String(text[range])
-            if let match = attributed.range(of: snippet) {
-                attributed[match].foregroundColor = Color(red: 0.0, green: 0.42, blue: 0.18)
-            }
+        colorProfileTokens(&attributed)
+        return attributed
+    }
+
+    /// Paints `$handle` and `[Derrick:handle]` on already-rendered text. Later copies of the same token are included.
+    public static func colorProfileTokens(_ attributed: inout AttributedString) {
+        let source = String(attributed.characters)
+        var search = attributed.startIndex
+        for range in AgentProfileTokenHighlight.ranges(in: source) {
+            let snippet = String(source[range])
+            guard !snippet.isEmpty, let match = attributed[search...].range(of: snippet) else { continue }
+            attributed[match].foregroundColor = profileTokenColor
+            search = match.upperBound
         }
+    }
+}
+
+/// Plain text with `$handle` and `[Derrick:handle]` in `HostUIMarkdown.profileTokenColor`.
+public struct HostUIProfileTokenText: View {
+    private let text: String
+    private let base: Color
+
+    public init(_ text: String, base: Color) {
+        self.text = text
+        self.base = base
+    }
+
+    public var body: some View {
+        Text(Self.attributed(text, base: base))
+    }
+
+    public static func attributed(_ text: String, base: Color) -> AttributedString {
+        var attributed = AttributedString(text)
+        attributed.foregroundColor = base
+        HostUIMarkdown.colorProfileTokens(&attributed)
         return attributed
     }
 }
@@ -25,30 +57,44 @@ extension AttributedString {
     }
 }
 
+/// How rendered markdown measures itself. Bubbles hug short copy. Documents fill the proposed width.
+public enum HostUIMarkdownSizing: Sendable {
+    case bubble
+    case document(maxIdealWidth: CGFloat)
+}
+
 public struct HostUIMarkdownText: View {
     private let text: String
     private let fontSize: CGFloat
-    private let maxIdealWidth: CGFloat
+    private let sizing: HostUIMarkdownSizing
 
     public init(_ text: String, font: Font = .system(size: 13), maxIdealWidth: CGFloat = HostUIMessagingLayout.maxBubbleWidth) {
         self.text = text
         // HostUI bubbles size via AppKit measurement; keep a numeric size.
         self.fontSize = 13
-        self.maxIdealWidth = maxIdealWidth
+        self.sizing = .bubble
         _ = font
+        _ = maxIdealWidth
     }
 
     public init(_ text: String, fontSize: CGFloat, maxIdealWidth: CGFloat = HostUIMessagingLayout.maxBubbleWidth) {
         self.text = text
         self.fontSize = fontSize
-        self.maxIdealWidth = maxIdealWidth
+        self.sizing = .bubble
+        _ = maxIdealWidth
+    }
+
+    public init(_ text: String, fontSize: CGFloat, sizing: HostUIMarkdownSizing) {
+        self.text = text
+        self.fontSize = fontSize
+        self.sizing = sizing
     }
 
     public var body: some View {
         HostUIMeasuringMarkdownText(
             attributedString: HostUIMarkdown.attributed(text),
             fontSize: fontSize,
-            maxIdealWidth: maxIdealWidth
+            sizing: sizing
         )
         .tint(Color(red: 0.176, green: 0.286, blue: 0.576))
     }
@@ -58,7 +104,7 @@ public struct HostUIMarkdownText: View {
 private struct HostUIMeasuringMarkdownText: NSViewRepresentable {
     let attributedString: AttributedString
     var fontSize: CGFloat = 13
-    var maxIdealWidth: CGFloat = 420
+    var sizing: HostUIMarkdownSizing = .bubble
 
     func makeCoordinator() -> Coordinator {
         Coordinator()
@@ -102,10 +148,7 @@ private struct HostUIMeasuringMarkdownText: NSViewRepresentable {
     ) -> CGSize? {
         apply(to: nsView)
         let proposed = proposal.width.flatMap { $0.isFinite && $0 > 1 ? $0 : nil }
-        let width = HostUIMessagingLayout.cappedBubbleWidth(
-            ideal: nsView.idealWidth(),
-            containerWidth: proposed
-        )
+        let width = measuredWidth(ideal: nsView.idealWidth(), proposed: proposed)
         let height = nsView.height(forWidth: width)
         return CGSize(width: width, height: height)
     }
@@ -115,6 +158,7 @@ private struct HostUIMeasuringMarkdownText: NSViewRepresentable {
         var styled = attributedString
         styled.font = Font(nsFont)
         styled.foregroundColor = Color(nsColor: .labelColor)
+        HostUIMarkdown.colorProfileTokens(&styled)
 
         let next = NSMutableAttributedString(attributedString: NSAttributedString(styled))
         next.enumerateAttribute(.link, in: NSRange(location: 0, length: next.length)) { value, range, _ in
@@ -130,6 +174,18 @@ private struct HostUIMeasuringMarkdownText: NSViewRepresentable {
         }
     }
 
+    private func measuredWidth(ideal: CGFloat, proposed: CGFloat?) -> CGFloat {
+        switch sizing {
+        case .bubble:
+            return HostUIMessagingLayout.cappedBubbleWidth(ideal: ideal, containerWidth: proposed)
+        case .document(let maxIdealWidth):
+            if let proposed {
+                return proposed
+            }
+            return min(max(ideal, 1), maxIdealWidth)
+        }
+    }
+
     final class Coordinator: NSObject, NSTextViewDelegate {
         func textView(_ textView: NSTextView, clickedOnLink link: Any, at charIndex: Int) -> Bool {
             let url: URL?

packages/HostUI/Sources/HostUI/HostUIMessagingControls.swift

@@ -157,16 +157,19 @@ public struct HostUIMessage: View {
             HStack(alignment: .center, spacing: 8) {
                 Image(systemName: "bubble.left.and.bubble.right")
                     .font(.caption.weight(.semibold))
+                    .foregroundStyle(row.replyCount > 0 ? HostUIMessagingLayout.navy : .primary.opacity(0.75))
                 VStack(alignment: .leading, spacing: 2) {
                     Text(replyTitle)
                         .font(.caption.weight(.semibold))
+                        .foregroundStyle(row.replyCount > 0 ? HostUIMessagingLayout.navy : .primary.opacity(0.75))
                     if row.replyCount > 0, let preview = row.replyPreview, !preview.isEmpty {
-                        // Plain one-line preview only — never expand the full thread body here.
-                        Text(HostUIMessagingLayout.collapsedReplyPreview(preview))
-                            .font(.caption2)
-                            .foregroundStyle(.secondary)
-                            .lineLimit(1)
-                            .truncationMode(.tail)
+                        HostUIProfileTokenText(
+                            HostUIMessagingLayout.collapsedReplyPreview(preview),
+                            base: .secondary
+                        )
+                        .font(.caption2)
+                        .lineLimit(1)
+                        .truncationMode(.tail)
                     }
                 }
             }
@@ -179,7 +182,6 @@ public struct HostUIMessage: View {
             )
         }
         .buttonStyle(.plain)
-        .foregroundStyle(row.replyCount > 0 ? HostUIMessagingLayout.navy : .primary.opacity(0.75))
         .fixedSize(horizontal: true, vertical: false)
     }
 

packages/HostUI/Sources/HostUI/HostUINodeView.swift

@@ -121,7 +121,7 @@ public struct HostUINodeView: View {
         HostUIPaneWidthReader {
             VStack(spacing: 0) {
             HStack {
-                Text(bindings.replyThreadTitle)
+                HostUIProfileTokenText(bindings.replyThreadTitle, base: .primary)
                     .font(.headline)
                     .lineLimit(1)
                 Spacer()

packages/HostUI/Tests/HostUITests/HostUIProfileTokenColorTests.swift

@@ -0,0 +1,31 @@
+import HostUI
+import Testing
+
+@MainActor
+@Suite struct HostUIProfileTokenColorTests {
+    @Test func dollarHandleAndSenderPrefixShareDarkGreen() {
+        let text = "$orchestrator then [Derrick:developer] done"
+        let attributed = HostUIMarkdown.attributed(text)
+        let snippets = attributed.runs.compactMap { run -> String? in
+            guard attributed[run.range].foregroundColor == HostUIMarkdown.profileTokenColor else {
+                return nil
+            }
+            return String(attributed[run.range].characters)
+        }
+        #expect(snippets == ["$orchestrator", "[Derrick:developer]"])
+    }
+
+    @Test func plainPreviewKeepsTheSameGreenOnTheSenderPrefix() {
+        let attributed = HostUIProfileTokenText.attributed(
+            "[Derrick:orchestrator] Searching the web…",
+            base: .secondary
+        )
+        let green = attributed.runs.compactMap { run -> String? in
+            guard attributed[run.range].foregroundColor == HostUIMarkdown.profileTokenColor else {
+                return nil
+            }
+            return String(attributed[run.range].characters)
+        }
+        #expect(green == ["[Derrick:orchestrator]"])
+    }
+}

packages/Structure/Sources/AgentRuntime/AgentProfile.swift

@@ -143,7 +143,7 @@ public enum AgentProfileTokenParser {
     }
 }
 
-/// Ranges of `$shortName` tokens (and the profile name inside `[Derrick:handle]`) for UI highlighting.
+/// Ranges of `$shortName` tokens and the full `[Derrick:handle]` sender prefix for UI highlighting.
 public enum AgentProfileTokenHighlight {
     public static func ranges(
         in text: String,
@@ -197,7 +197,8 @@ public enum AgentProfileTokenHighlight {
             guard let close = text[handleStart...].firstIndex(of: "]") else { break }
             let handle = String(text[handleStart..<close])
             if isHighlightableHandle(handle) {
-                ranges.append(handleStart..<close)
+                let tokenEnd = text.index(after: close)
+                ranges.append(prefix.lowerBound..<tokenEnd)
             }
             searchFrom = close
             if searchFrom < text.endIndex {

packages/Structure/Tests/StructureTests/AgentProfileTests.swift

@@ -106,7 +106,7 @@ import Testing
 
         let outbound = "[Derrick:developer] Fixed the build."
         let outboundTokens = AgentProfileTokenHighlight.ranges(in: outbound).map { String(outbound[$0]) }
-        #expect(outboundTokens == ["developer"])
+        #expect(outboundTokens == ["[Derrick:developer]"])
 
         let ignored = AgentProfileTokenHighlight.ranges(in: "price is $100")
         #expect(ignored.isEmpty)