[BUG] copyOnSelect: false is ignored by the fullscreen renderer (honored by the default renderer) — v2.1.206

Summary
copyOnSelect is a real, implemented setting — but the fullscreen renderer bypasses it. With "tui": "fullscreen" and "copyOnSelect": false, a mouse drag-select still copies to the clipboard (via OSC 52). Switching to the default/classic renderer with the same settings correctly suppresses the copy.

What I want: keep tui: fullscreen AND have copyOnSelect: false actually disable copy-on-select. copyOnSelect is the toggle for this; it just isn't consulted by the fullscreen path.

Environment

• Claude Code 2.1.206, Linux x86_64, run on a remote headless host over SSH
• Client: iTerm2 / macOS. TERM=xterm-256color
• No xclip / xsel / wl-copy on the remote host → the copy path falls back to OSC 52 up the SSH pipe, writing to the client's clipboard

Repro

1. On a remote Linux host, ~/.claude/settings.json: { "tui": "fullscreen", "copyOnSelect": false }
2. Start a fresh claude session (so the setting is definitely loaded).
3. Drag-select any text in the TUI.
4. Actual: the client's system clipboard is overwritten (OSC 52 emitted).
5. Run the same session with the classic renderer, settings unchanged:

CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN=1 claude

1. Drag-select again. Clipboard is untouched — copyOnSelect: false is honored here.

Expected: copyOnSelect: false suppresses copy-on-select in both renderers, including fullscreen.

Why this is a bypass, not a missing feature
copyOnSelect is present and read in the 2.1.206 bundle. It appears in the settings key groups ("Input & controls": [... "copyOnSelect" ...]), has a settings-UI toggle ({ id: "copyOnSelect", label: "Copy on select", type: "boolean" }), and gates the copy:

if (!(St().copyOnSelect ?? true)) return;   // early-return when false
let u = e.copySelectionNoClear();

The fullscreen renderer reaches the clipboard write through a different path that never consults this gate.

Impact
On any headless/remote host, every incidental drag-select in the TUI silently clobbers the local machine's clipboard over OSC 52. copyOnSelect: false is the documented opt-out and does not work on fullscreen — so there is currently no way to use the fullscreen renderer without this. Workarounds all sacrifice something: CLAUDE_CODE_DISABLE_MOUSE=1 loses wheel scroll; CLAUDE_CODE_DISABLE_MOUSE_CLICKS=1 still requires Shift/Option to select.

Ask: make the fullscreen selection path honor the existing copyOnSelect gate.

Related (but distinct): #60755 and #29030 request copyOnSelect as a new feature — it already exists. #72455 / #70857 / #71926 / #74320 report fullscreen clipboard/selection problems generally. This is narrower and directly actionable.