Two ways to copy chat content out of the TUI now work:

1. In-app selection (Ctrl+C, OSC 52): _ChatItemView.render() now builds a
   selection-aware Content from the rich renderable instead of letting Static
   wrap a Panel into a non-selection-aware RichVisual — so the magenta
   drag-select highlight actually renders and get_selection returns clean,
   chrome-free text. rich Segment styles are converted to Textual Style
   (Style.from_rich_style) so the selection_style merge doesn't crash, and
   None segment styles are guarded. get_content_height is overridden to
   compute auto-height straight from the rich renderable; without it the
   width-keyed Content churned new Visual objects per width change and spread
   the layout-settling cascade across refreshes, leaving a deferred scroll_end
   at an intermediate max_scroll_y (chat no longer stuck to bottom). Theme
   defines screen-selection-background/foreground so the highlight is visible.

2. Reading mode (Ctrl+R) for terminals without OSC 52 (e.g. GNOME Console,
   TERM_PROGRAM=kgx, which silently ignores OSC 52 so Ctrl+C never reaches the
   OS clipboard). Toggling the app's reading-mode class hides the chrome around
   the chat (right status/todo column, input prompt, status bar, chat outer
   border) and re-renders every message without its Panel borders via the
   registry's new render_plain — so Shift+drag + Ctrl+Shift+C copies just the
   conversation text to the system clipboard. ContentRenderer.render_plain
   defaults to unwrapping Panel/Padding(Panel) to its body; assistant messages
   and plan_ready override it to raw Text(content) so rich Markdown doesn't
   re-wrap fenced code blocks in their own bordered Panels. ChatPanel tracks
   reading mode and re-renders visible widgets in place (scroll preserved);
   new streamed items pick up the mode on mount.

Help (/help) now lists keys and documents both copy paths.

Tests: render_plain parametrized across all item types, message renderer
plain tests, chat panel reading-mode toggle (borders off/on, scroll kept,
new items borderless), tui_app reading-mode chrome hide, plus the existing
selection suite. Full suite green (922 passed, 1 skipped).

Sub-agent activity was either rendered as a generic tool card (spawn_agent) or
dropped to raw debug output (turn_thinking was unhandled in the TUI chat model
and the raw CLI). The webclient nests subagent events inside the spawn_agent
card; the TUI is flat, so nesting is conveyed with a distinct spawn card plus
left-indented, dimmed subagent cards.

New renderers/subagent.py:
- SpawnAgentStartedRenderer: "↘ subagent · <profile_id>" card showing the task
  (+ briefing dimmed), secondary border. Registered before ToolStartedRenderer.
- SpawnAgentResultRenderer: "↙ subagent · <profile_id> ✓/✗" card with the
  result, success/error border. Registered before ToolResultRenderer.

Nested subagent styling (left indent via Padding + dim):
- ThinkingRenderer: is_subagent → "subagent thinking" title, dim border, indented.
- PlanningStatusRenderer / PlanReadyRenderer: is_subagent → indented (label/title
  already mark it as subagent).
- ToolStartedRenderer / ToolResultRenderer: is_subagent → indented so inner
  tool calls read as nested inside the spawn card.

chat_model handles turn_thinking → thinking_block item with is_subagent meta;
chat_panel._refresh forwards is_subagent to the thinking renderer. Raw CLI
render.py prints turn_thinking as a [thinking] block (with "(subagent)" prefix).

Tests: spawn card shows profile/task and status; subagent thinking/planning/tool
cards are indented and labeled; non-subagent tool card is not indented;
turn_thinking creates a subagent thinking_block. 593 passed, 1 skipped.

Co-Authored-By: Claude <noreply@anthropic.com>

planning_status and plan_ready events were unhandled in the TUI chat model and
the raw CLI renderer, so they fell through to raw debug output (TUI:
"plan_ready: {...}" status lines; raw CLI: "[event: plan_ready] {msg}").

TUI:
- New renderers/planning.py: PlanningStatusRenderer renders a "⚙ Planning ·
  <label>" line (info color; dim + "(subagent)" prefix for subagent planning);
  PlanReadyRenderer renders the plan as a Panel wrapping themed Markdown, titled
  "Plan" with an accent border ("subagent plan" + dim border for subagents).
- Registered both in default_registry().
- chat_model handles the events: non-subagent planning_status rolls in place
  (Analysis → Execution plan → Plan review share one line instead of stacking);
  plan_ready consumes the pending planning line and appends the plan card;
  subagent planning is appended as its own dim line/card so it does not bleed
  into the parent turn's indicator (matching the webclient).
- chat_panel._refresh maps the new kinds to the registry.

Raw CLI (render.py): planning_status prints "[planning] <label>"; plan_ready
prints a "[plan] … [/plan]" block with the plan text.

Tests: renderer accepts/render (label, subagent prefix, plan title/content);
chat_model rolling-in-place, plan_ready consumes indicator, subagent separation.
584 passed, 1 skipped.

Co-Authored-By: Claude <noreply@anthropic.com>