Remove the stdio agent

.agents/notes/implemented/feature/2026-07-17-dedicated-full-screen-tui-front-door.md

@@ -6,7 +6,7 @@ English | [中文](2026-07-17-dedicated-full-screen-tui-front-door.zh.md)
 
 ## Problem
 
-The line-oriented `@deepseek-ai/dsh-stdio` front door works in pipes and ordinary terminals, but a full-screen coding interface must own raw input, differential screen drawing, cursor state, overlays, and terminal restoration. Combining those contracts in one UI plugin couples the pipe-safe path to a TTY-only lifecycle and makes it unclear which terminal behavior a composition selects.
+At the time this front door was introduced, the line-oriented agent handled pipes and ordinary terminals, but a full-screen coding interface had to own raw input, differential screen drawing, cursor state, overlays, and terminal restoration. Combining those contracts in one UI plugin would have coupled a stream-oriented path to a TTY-only lifecycle. The later [remove-stdio-agent decision](../simplification/2026-07-20-remove-stdio-agent.md) removes that redundant line agent; this Note continues to own the TUI design.
 
 The interactive channel must remain a Cordis plugin over the same agent, session, tool, and user-interaction services as every other front door. It needs to resume durable history, follow compaction replacements, display tool-owned presentation, and restore the terminal on startup failure and disposal. A standalone chat application or a second agent composition would duplicate behavior outside the plugin graph.
 
@@ -14,7 +14,7 @@ The interactive channel must remain a Cordis plugin over the same agent, session
 
 DeepSeek Harness ships [`@deepseek-ai/dsh-tui`](../../../../packages/ui/tui/README.md) as a dedicated Cordis plugin. It owns terminal input and presentation only; agent lifecycle, session persistence, tool execution, and the model-facing question tool remain separate composition entries. The plugin requires both stdin and stdout to be TTYs and fails instead of silently changing to line-oriented behavior.
 
-The app layer selects a concrete terminal front door before mounting it. `@deepseek-ai/dsh-stdio-demo` can resolve `auto` from the two process streams, while the `repl-agent` and `tui-agent` leaves explicitly select readline and TUI respectively. The TUI leaf reuses the repl-agent backend and tool composition through an asserted include patch, so the three runnable agent leaves remain symmetric without duplicating deployment choices.
+The app layer has one terminal front door. `@deepseek-ai/dsh-tui-demo` mounts the TUI before the configured agent, and `examples/tui-agent` owns the interactive coding composition and Code Mode overlay directly. Non-interactive tasks use `@deepseek-ai/dsh-cli-demo`; ACP remains a separate editor protocol.
 
 The selected front door receives the exact generated or resumed `SessionId` used by the pre-created agent. It mounts before the agent composition, waits for the matching root agent, and enters full-screen mode only after that agent exists. A matching `agent-loop/config-start-failed` event is therefore reported before screen takeover and exits with status 1.
 
@@ -42,7 +42,7 @@ The implemented [TUI terminal-state snapshot Agent Note](../testing/2026-07-18-t
 
 ## Consequences
 
-- Interactive terminal work gains a stateful Markdown, card, plan, and question interface without changing the line-oriented protocol used by pipes and automation.
-- The TUI carries a pi-tui dependency and a strict TTY requirement; non-TTY deployments select `@deepseek-ai/dsh-stdio` at composition time.
+- Interactive terminal work has a stateful Markdown, card, plan, and question interface with no second terminal protocol to keep aligned.
+- The TUI carries a pi-tui dependency and a strict TTY requirement; non-TTY deployments use the Headless app or a structured protocol.
 - Session projection makes resume and compaction consistent with the durable conversation, but one configured session owns the transcript and editor.
 - Tool packages extend terminal cards through their existing presentation methods without adding tool-specific branches to the TUI.