fix(tui): hide plugin-injected system reminders from transcript

[li-xiu-qi]

Closes #33

Problem

The subagent-plugin injects a Delegation reminder system message via beforeModelRequest on every user turn. Because the TUI renders every system message, the reminder appears repeatedly in the conversation transcript, cluttering the UI. Plan-plugin and skill-plugin inject similar internal status messages that also leak into the transcript.

Solution

Add an optional hidden flag to plugin-injected system messages. Hidden messages are still included in the model context (so behavior is unchanged), but they are skipped by the TUI transcript renderer and clipboard export.

Changes

• packages/protocol/src/index.ts: add hidden?: boolean to SystemMessage.
• packages/core/src/plugins/types.ts: add hidden?: boolean to PluginInjectedMessage.
• packages/core/src/plugins/manager.ts: preserve the hidden flag when aggregating injected messages.
• packages/core/src/agent/agent-loop.ts: pass hidden from injected messages into memory.
• packages/core/src/agent/conversation-memory.ts: preserve hidden when cloning/restoring system messages so it survives checkpoints.
• src/runtime/local-opentui-bridge.ts: forward hidden to transcript entries.
• src/tui/types.ts: add hidden?: boolean to StepCliTuiTranscriptEntry.
• src/tui/app.tsx: filter hidden entries out of buildTranscriptItems.
• src/tui/transcript-export.ts: filter hidden entries from clipboard export.
• skills/builtin/src/subagent-plugin.ts: mark MAIN_ORCHESTRATION_REMINDER as hidden: true.
• skills/builtin/src/plan-plugin.ts: mark plan-status injection as hidden: true.
• skills/builtin/src/skill-plugin.ts: mark skill-context injection as hidden: true.

Verification

• pnpm exec tsc --noEmit passes.
• pnpm build succeeds.
• pnpm exec vitest run packages/core/src/agent/conversation-memory.test.ts packages/core/src/agent/conversation-memory-checkpoint.test.ts passes (23/23).
• pnpm check passes after chore(docs): format pr-review-decision.md with Prettier #38 (formatting fix) is applied; only pre-existing lint warnings remain.
• The TUI launches without errors and no longer renders repeated SYSTEM Delegation reminder / Plan status / Skill context blocks.

Related

• chore(docs): format pr-review-decision.md with Prettier #38 fixes the unrelated Prettier formatting warning in docs/skills/pr-review-decision.md.

[ZouR-Ma]

Thanks for the contribution!

To get this ready to merge:

• Reference an issue in the description with Closes #<number> (our link-check CI requires it; open one first if needed).
• Make sure pnpm check passes locally (lint, type-check, dependency/dead-code guards, formatting, and tests — also enforced in CI).

Full conventions:
https://github.com/stepfun-ai/Step-Realtime-CLI/blob/main/CONTRIBUTING.md

[li-xiu-qi]

@ZouR-Ma Thanks for the review. I've rebased onto the latest main and confirmed pnpm check passes locally (Node 20.20.2). The PR description already references Closes #33. Please let me know if anything else is needed.

[ZouR-Ma]

Thanks for this PR — the design choice is right: an optional hidden flag on system messages, still delivered to the model context and only skipped at render and export time, is far more robust than content-pattern filtering. The details are also thought through: cloneChatMessage preserves the flag so it survives checkpoints, and the conditional spread in addSystem avoids stamping hidden: false onto every message. One thing before this lands:

1. (Must) Add a test for hidden-flag persistence. The flag-preserving line in cloneChatMessage is the one link in this chain that a future refactor could silently drop — the clutter bug would return with no failing test. Please add a case to the existing packages/core/src/agent/conversation-memory.test.ts: after addSystem(content, { hidden: true }), run a clone/restore round-trip and assert the flag is still true; also assert that an unflagged message comes back without a hidden field. Acceptance criterion: the case exists and passes.

Two non-blocking suggestions besides that: PluginInjectedMessage allows role: "user" with a hidden flag, but the user branch in agent-loop silently ignores it — the builtin plugins only inject system messages so it never triggers today, but a third-party plugin would hit it; consider tightening the type or documenting "system-only" on the field. Also, your #69 and #72 overlap with this PR on app.tsx and local-opentui-bridge.ts — it's worth sequencing the three yourself; this one is the smallest, so landing it first minimizes the rebase churn for the other two. Ping us once the test is in.

[li-xiu-qi]

@ZouR-Ma Thanks for the review. I've added a test case to packages/core/src/agent/conversation-memory.test.ts covering hidden-flag persistence through an export/load round-trip:

• addSystem(content, { hidden: true }) survives exportState -> loadState -> exportState with hidden still true.
• An unflagged system message comes back without a hidden field.

pnpm test packages/core/src/agent/conversation-memory.test.ts passes (13/13), and pnpm exec tsc --noEmit is clean.

Please take another look when you have a moment.

[ZouR-Ma]

Re-review passed — this is ready to land. The new test is exactly the one we asked for: preserves hidden flag through export/load round-trip locks down the flag-preserving line in cloneChatMessage (the one fragile link in the whole chain), and it also asserts that unflagged messages come back without a hidden field — both halves of the acceptance criterion. All three CI lanes are green.

The one leftover from the review — PluginInjectedMessage allowing role: "user" with a hidden flag that the agent loop silently ignores — we took care of directly on this branch (maintainer edit, 7a626a9) so it doesn't cost you another round: the type is now a discriminated union where hidden only exists on the system variant, with the constraint documented on the field. Typecheck and the plugin/memory test suites pass; we also merged the latest main.

Merging once CI reruns on that touch-up. Your #69 and #72 overlap with this PR on a couple of files — worth rebasing them once this lands. Thanks for turning the test around the same day.

[ZouR-Ma]

The hidden-persistence test matches the acceptance criterion exactly, the type is now tightened so the hidden flag only exists on system messages, and all required checks are green on the merged state. Approving.