fix(tui): stabilize Windows terminal snapshots

Treat an absolute path.relative() result as a cross-volume path instead of incorrectly abbreviating it beneath the user's home directory.

Allow embeddings to project a logical footer cwd without changing the operational session cwd. The recorded-session harness now uses a POSIX-shaped display alias for both the footer and filesystem result paths, preserving the existing pre-normalization layout width on every host.

Keep runtime-provided labels behind terminal-control escaping, cover that boundary, and document the embedding contract.

packages/ui/tui/tests/harness.ts

@@ -5,7 +5,7 @@ import type { ContentBlock } from '@deepseek-ai/dsh-llm'
 import SessionStore, { SessionId, type Session } from '@deepseek-ai/dsh-session'
 import type { ToolDefinition } from '@deepseek-ai/dsh-tools'
 import UserInteractionService from '@deepseek-ai/dsh-user-interaction'
-import { createTuiChat, type Config } from '../src/index.ts'
+import { createTuiChat, type Config, type TuiRuntime } from '../src/index.ts'
 
 interface FakeAgent extends Agent {
   status: AgentStatus
@@ -21,6 +21,7 @@ export interface TuiHarnessOptions {
   configureContext?: (ctx: Context) => Promise<void>
   beforeMount?: (session: Session) => void
   cwd?: string | null
+  formatCwd?: TuiRuntime['formatCwd']
 }
 
 export interface TuiHarness<TerminalType extends Terminal, Exit extends (code: number) => void> {
@@ -95,7 +96,11 @@ export async function createTuiTestHarness<TerminalType extends Terminal, Exit e
     welcome: 'Coding agent ready.',
     sessionId,
     color: false,
-  }, options.config), { terminal, exit })
+  }, options.config), {
+    terminal,
+    exit,
+    ...(options.formatCwd === undefined ? {} : { formatCwd: options.formatCwd }),
+  })
   return { ctx, session, agent, terminal, exit, controller }
 }