plugin install spinner outputs garbage in non-TTY environment

[lunqin123]

Description

When running opencode plugin install <package> from a non-interactive shell (e.g., PowerShell, subprocess, CI), the spinner animation frames are printed as individual lines instead of being rendered in-place as an animation.

Reproduction

1. Run from PowerShell: opencode plugin install opencode-session-search
2. Observe the output: each spinner frame (◓, ◑, ◒, ◐) appears on its own line with "Installing plugin package..." repeated

Root Cause

The plugin install command uses TUI spinner escape sequences (\r + ANSI CSI) without checking whether stdout is a TTY (via isatty). In non-interactive environments, carriage returns are not interpreted, so each frame becomes a separate line of output.

Expected Behavior

• In TTY: inline spinner animation (current behavior, correct)
• In non-TTY: simple static text like "Installing plugin package..." without escape sequences, or just silent with exit code

Environment

• OpenCode v1.15.3 (probably affects all versions)
• Windows 11, PowerShell 7
• Also affects CI/CD and subprocess invocations

Suggested Fix

Add an isatty check (e.g., Go's term.IsTerminal or Node's process.stdout.isTTY) before outputting spinner sequences. Fall back to plain text or no output when stdout is not a terminal.

[simonklee]

Thanks for reporting.

[GitNimay]

Hi! I’d like to work on this issue. My plan is to make the plugin install status output TTY-aware so interactive shells keep the spinner while non-interactive runs fall back to plain log lines, then cover that behavior with a focused test. I’ll have a draft PR up within a few hours.