fix(tui): restore session header card

tui/src/app.test.ts

@@ -283,9 +283,11 @@ describe("NanobotTui layout", () => {
       composer: { backgroundColor: { intent: string }; textColor: { toInts(): number[] } }
       transcript: {
         markdown: Set<{ syntaxStyle: object }>
+        frames: Set<{ borderColor: { toInts(): number[] } }>
       }
     }
     const markdown = [...internals.transcript.markdown][0]
+    const sessionFrame = [...internals.transcript.frames][0]
     const darkSyntax = markdown?.syntaxStyle
 
     setup.renderer.emit(CliRenderEvents.THEME_MODE, "light")
@@ -299,6 +301,7 @@ describe("NanobotTui layout", () => {
     expect(internals.shell.backgroundColor.intent).toBe("default")
     expect(internals.composer.backgroundColor.intent).toBe("default")
     expect(internals.composer.textColor.toInts().slice(0, 3)).toEqual([24, 24, 27])
+    expect(sessionFrame?.borderColor.toInts().slice(0, 3)).toEqual([212, 212, 216])
     expect(markdown?.syntaxStyle).not.toBe(darkSyntax)
   })
 
@@ -316,10 +319,14 @@ describe("NanobotTui layout", () => {
     const userLine = frame.split("\n").find((line) => line.includes("User question")) || ""
     const agentLine = frame.split("\n").find((line) => line.includes("Agent **answer**")) || ""
     const headerLine = frame.split("\n").find((line) => line.includes(">_  nanobot")) || ""
+    const headerBorder = frame.split("\n").find((line) => line.includes("╭")) || ""
 
     expect(userLine).toContain("› User question")
     expect(agentLine).toContain("• Agent **answer**")
-    expect(headerLine).not.toMatch(/[╭╮│]/u)
+    expect(userLine).not.toContain("│")
+    expect(agentLine).not.toContain("│")
+    expect(headerLine).toContain("│")
+    expect(headerBorder.trim().length).toBeLessThanOrEqual(62)
   })
 
   test("keeps footer status and shortcuts visually separated", async () => {

tui/src/app.ts

@@ -117,6 +117,7 @@ function transcriptTheme(palette: Palette): TranscriptTheme {
     error: palette.error,
     user: palette.user,
     assistant: palette.accent,
+    border: palette.border,
     syntax: syntaxStyle(palette),
   }
 }

tui/src/transcript.ts

@@ -17,6 +17,7 @@ export interface TranscriptTheme {
   error: string
   user: string
   assistant: string
+  border: string
   syntax: SyntaxStyle
 }
 
@@ -47,6 +48,7 @@ export class Transcript {
   }> = []
   private readonly markdown = new Set<MarkdownRenderable>()
   private readonly activities = new Set<Activity>()
+  private readonly frames = new Set<BoxRenderable>()
   private wrote = false
   private nextId = 0
 
@@ -84,6 +86,7 @@ export class Transcript {
     this.theme = theme
     for (const { renderable, tone } of this.styledText) renderable.fg = theme[tone]
     for (const renderable of this.markdown) renderable.syntaxStyle = theme.syntax
+    for (const frame of this.frames) frame.borderColor = theme.border
     // Markdown may still be rendering this frame. Release the prior native
     // style only after the renderer reaches idle, matching OpenCode's retained
     // theme lifecycle and avoiding both leaks and use-after-free transitions.
@@ -91,15 +94,27 @@ export class Transcript {
   }
 
   header(options: TranscriptHeader): void {
-    const row = this.createRow("header")
+    const row = new BoxRenderable(this.renderer, {
+      id: this.id("header-row"),
+      width: "100%",
+      maxWidth: 62,
+      flexDirection: "column",
+      border: true,
+      borderStyle: "rounded",
+      borderColor: this.theme.border,
+      paddingLeft: 1,
+      paddingRight: 1,
+    })
     const title = this.createText(`>_  nanobot  v${options.version}`, "text", true)
     const context = this.createText([
+      "",
       `${options.model}  ·  ${options.access}`,
       options.workspace,
     ].join("\n"), "muted")
     row.add(title)
     row.add(context)
     this.root.add(row)
+    this.frames.add(row)
     this.wrote = true
   }
 
@@ -113,6 +128,7 @@ export class Transcript {
     this.styledText.length = 0
     this.markdown.clear()
     this.activities.clear()
+    this.frames.clear()
     this.wrote = false
     this.nextId = 0
     this.header(header)
@@ -229,6 +245,7 @@ export class Transcript {
   destroy(): void {
     this.live = null
     this.activity = null
+    this.frames.clear()
     this.theme.syntax.destroy()
   }