feat(tui): per-section visibility for the details accordion

[OutThisLife]

Summary

Two changes that together let users shape exactly what the TUI shows:

1. Opinionated per-section defaults. Out of the box the TUI now streams the turn as a live transcript — reasoning and tool calls render inline, the activity noise feed is silenced, spawn trees stay quiet until a delegation actually happens. Driven by the request: "all that I want to see is thinking, content/midstream content, and tools, always — no errors/warnings".
2. Per-section visibility overrides. New optional display.sections map lets users override visibility for any subset of sections without affecting the rest. Pairs with the existing global details_mode.

Default matrix

Section	Default	Rationale
thinking	expanded	Reasoning streams inline as the model emits it.
tools	expanded	Tool calls + results render open.
subagents	falls through to details_mode (collapsed)	Stays quiet until a delegation actually happens.
activity	hidden	Ambient meta (gateway hints, terminal-parity nudges, background notifications) is noise for typical use. Tool failures still render inline on the failing tool row; ambient errors/warnings surface via a floating-alert backstop when every panel is hidden.

Streaming/midstream assistant content is unaffected — it always renders inline, it's not part of the section accordion.

Opting out

Everything explicit in display.sections wins over the built-in defaults, so existing configs keep working unchanged. To reshape the layout:

display:
  details_mode: collapsed       # global fallback (existing — unchanged)
  sections:
    thinking: collapsed         # put thinking back under a chevron
    tools: collapsed            # put tool calls back under a chevron
    activity: collapsed         # opt the activity panel back in
    subagents: expanded         # always open spawn tree

Or at runtime: /details <section> [hidden|collapsed|expanded|reset].

Slash command

Extended /details:

• /details — show current global + active overrides
• /details [hidden|collapsed|expanded|cycle] — set global mode (existing)
• /details <section> [hidden|collapsed|expanded|reset] — per-section override (new)

Sections: thinking, tools, subagents, activity. Per-section overrides take precedence over both the section default and the global mode — so details_mode: hidden + sections.tools: expanded renders the tools panel even when the global mode is hidden.

Implementation

• ui-tui/src/types.ts — SectionName + SectionVisibility types.
• ui-tui/src/domain/details.ts — resolveSections, isSectionName, SECTION_NAMES, plus SECTION_DEFAULTS (thinking/tools expanded, activity hidden) and sectionMode which resolves explicit override → SECTION_DEFAULTS → global. Single source of truth for "what mode does this section render in".
• ui-tui/src/app/{interfaces,uiStore,useConfigSync}.ts — sections (the explicit-overrides map) threaded into UiState, parsed from display.sections on initial config sync.
• ui-tui/src/components/thinking.tsx — ToolTrail consumes per-section modes via sectionMode. Hidden sections are skipped entirely; expanded ones seed open state to true. Renamed the local sections array to panels to avoid shadowing the new prop. Early-return now keys off allHidden (every section resolved to hidden) so per-section overrides still render when the global mode is hidden; floating-alert backstop surfaces under that all-hidden case.
• ui-tui/src/components/{messageLine,appLayout}.tsx — pass sections through; skip the trail wrapper only when every section resolves to hidden.
• ui-tui/src/app/useMainApp.ts — showProgressArea rebuilt around anyPanelVisible (mirrors ToolTrail's short-circuit, kills the empty-wrapper-Box cosmetic gap).
• ui-tui/src/app/slash/commands/core.ts — /details <section> <mode> parsing + dispatch via config.set with details_mode.<section> key. reset clears the override.
• tui_gateway/server.py — config.set details_mode.<section> handler writes to display.sections.<section>. Empty value clears the override. Validation rejects unknown sections / unknown modes with 4002.
• website/docs/user-guide/tui.md — documented defaults, overrides, and the opt-out story.

Behavioural changes for existing users

• Most users: thinking + tools panels now stream expanded by default; activity panel disappears; spawn trees unchanged. Tool failures still surface inline; ambient hints (e.g. "tmux detected", "Apple Terminal detected") no longer clutter the transcript chrome.
• Users on details_mode: expanded: no visible change — thinking/tools were already open; activity is now hidden but gets a floating backstop for errors.
• Users on details_mode: hidden (legacy quiet mode): thinking + tools now render open regardless (section defaults win over the global). To restore silence: pin each section explicitly (display.sections.thinking: hidden, etc.).
• Users who already set display.sections entries: their overrides win. No migration needed.

One config line reverts each default in every case.

Test plan

• vitest run (ui-tui) — 272/272 passing (17 new: 6 domain, 4 config sync, 3 slash, 3 gateway, 1 override-escapes-hidden regression)
• tsc --noEmit (ui-tui) — clean (the pre-existing dom.ts warning on main is untouched)
• pytest tests/test_tui_gateway_server.py -k config_set_section — 3/3
• Copilot review threads (3) — addressed + resolved
• Manual: fresh ~/.hermes/ directory → run hermes --tui → thinking + tools stream open, activity never surfaces, spawn tree stays collapsed until a delegation fires
• Manual: /details thinking collapsed → thinking back under a chevron + persists to config; /details thinking reset → restores the new default (expanded)
• Manual: details_mode: hidden + sections.tools: expanded → tools panel still renders (regression coverage for Copilot's catch)

[Copilot]

Pull request overview

Adds per-section visibility overrides for the TUI “details” accordion (thinking/tools/subagents/activity), with the activity panel now hidden by default, plus config + slash-command plumbing end-to-end (TUI ↔ gateway ↔ docs/tests).

Changes:

• Introduces display.sections per-section overrides resolved via a shared sectionMode() helper (activity defaults to hidden).
• Threads sections through UI state/config sync and down into transcript rendering (ToolTrail).
• Extends /details to support per-section overrides and persists them via config.set details_mode.<section> (gateway writes to display.sections.<section>).

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
website/docs/user-guide/tui.md	Documents new defaults, per-section overrides, and /details syntax.
ui-tui/src/types.ts	Adds SectionName and SectionVisibility types for per-section overrides.
ui-tui/src/gatewayTypes.ts	Extends display config shape to include sections.
ui-tui/src/domain/details.ts	Adds section parsing, validation, defaults, and sectionMode() resolver.
ui-tui/src/components/thinking.tsx	Applies per-section modes to ToolTrail panels; hides activity by default; adjusts expand-all behavior.
ui-tui/src/components/messageLine.tsx	Passes sections through to ToolTrail for per-message rendering.
ui-tui/src/components/appLayout.tsx	Threads sections into streaming/progress and transcript rendering.
ui-tui/src/app/useConfigSync.ts	Parses display.sections from gateway config into UI state.
ui-tui/src/app/uiStore.ts	Initializes sections in the default UI store state.
ui-tui/src/app/slash/commands/core.ts	Extends /details parsing and persists per-section overrides via config.set.
ui-tui/src/app/interfaces.ts	Adds sections to UiState.
ui-tui/src/tests/useConfigSync.test.ts	Adds tests for parsing/dropping invalid display.sections.
ui-tui/src/tests/details.test.ts	Adds unit tests for section parsing/validation and default resolution.
ui-tui/src/tests/createSlashHandler.test.ts	Adds tests for /details <section> … set/reset/usage behavior.
tui_gateway/server.py	Implements config.set details_mode.<section> → display.sections.<section> with validation.
tests/test_tui_gateway_server.py	Adds pytest coverage for per-section config set/clear/validation.

Comments suppressed due to low confidence (1)

ui-tui/src/components/appLayout.tsx:67

• progress.showProgressArea can be true in modes where <ToolTrail …/> intentionally returns null (e.g., global detailsMode: hidden with activity resolved to hidden). In that case this wrapper <Box> will still render and may introduce a blank gap in the streaming area. Consider suppressing the wrapper when the effective activity section is hidden (or otherwise ensuring showProgressArea is false in that case).

      {progress.showProgressArea && (
        <Box flexDirection="column" marginBottom={progress.showStreamingArea ? 1 : 0}>
          <ToolTrail
            activity={progress.activity}
            busy={busy}
            detailsMode={detailsMode}
            outcome={progress.outcome}
            reasoning={progress.reasoning}
            reasoningActive={progress.reasoningActive}
            reasoningStreaming={progress.reasoningStreaming}
            reasoningTokens={progress.reasoningTokens}
            sections={sections}
            subagents={progress.subagents}
            t={t}
            tools={progress.tools}
            toolTokens={progress.toolTokens}
            trail={progress.turnTrail}
          />
        </Box>

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[Copilot]

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

ui-tui/src/components/messageLine.tsx:113

• showDetails (computed above this block) currently short-circuits on detailsMode !== 'hidden', so when the global mode is hidden this ToolTrail never mounts for normal assistant messages—even if per-section overrides (or built-in section defaults) would resolve thinking/tools to expanded.

To make per-section visibility truly override global hidden (as /details <section> … and sectionMode() imply), compute showDetails using sectionMode() for the sections that actually have content (e.g., show when (thinking && thinkingMode!==hidden) or (msg.tools?.length && toolsMode!==hidden)), rather than checking only the global mode.

      {showDetails && (
        <Box flexDirection="column" marginBottom={1}>
          <ToolTrail
            detailsMode={detailsMode}
            reasoning={thinking}
            reasoningTokens={msg.thinkingTokens}
            sections={sections}
            t={t}
            toolTokens={msg.toolTokens}
            trail={msg.tools}
          />
        </Box>

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