Copilot review on #14968 caught that the early returns gated on the
global `detailsMode === 'hidden'` short-circuited every render path
before sectionMode() got a chance to apply per-section overrides — so
`details_mode: hidden` + `sections.tools: expanded` was silently a no-op.
Three call sites had the same bug shape; all now key off the resolved
section modes:
- ToolTrail: replace the `detailsMode === 'hidden'` early return with
an `allHidden = every section resolved to hidden` check. When that's
true, fall back to the floating-alert backstop (errors/warnings) so
quiet-mode users aren't blind to ambient failures, and update the
comment block to match the actual condition.
- messageLine.tsx: drop the same `detailsMode === 'hidden'` pre-check
on `msg.kind === 'trail'`; only skip rendering the wrapper when every
section resolves to hidden (`SECTION_NAMES.some(...) !== 'hidden'`).
- useMainApp.ts: rebuild `showProgressArea` around `anyPanelVisible`
instead of branching on the global mode. This also fixes the
suppressed Copilot concern about an empty wrapper Box rendering above
the streaming area when ToolTrail returns null.
Regression test in details.test.ts pins the override-escapes-hidden
behaviour for tools/thinking/activity. 271/271 vitest, lints clean.
The activity panel (gateway hints, terminal-parity nudges, background
notifications) is noise for the typical day-to-day user, who only cares
about thinking + tools + streamed content. Make `hidden` the built-in
default for that section so users land on the quiet mode out of the box.
Tool failures still render inline on the failing tool row, so this
default suppresses the noise feed without losing the signal.
Opt back in with `display.sections.activity: collapsed` (chevron) or
`expanded` (always open) in `~/.hermes/config.yaml`, or live with
`/details activity collapsed`.
Implementation: SECTION_DEFAULTS in domain/details.ts, applied as the
fallback in `sectionMode()` between the explicit override and the
global details_mode. Existing `display.sections.activity` overrides
take precedence — no migration needed for users who already set it.
