fix(terminal): correct CSI handler params for DECRQM workaround

[arnestrickmann]

Summary

• Fixes crash when spawning OpenCode CLI: Cannot read properties of undefined (reading '0') at TerminalSessionManager.ts:215
• The registerCsiHandler callback receives params as (number | number[])[] directly, not as an object with a .params property — the code was accessing params.params[0] which is undefined
• The bug existed since the DECRQM workaround was added but was never triggered until OpenCode sent mode-query escape sequences

Test plan

• Spawn OpenCode CLI agent — should no longer crash
• Spawn Amp agent — DECRQM workaround still functions correctly
• Other CLI agents (Claude Code, Codex, etc.) unaffected

🤖 Generated with Claude Code

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Project	Deployment	Actions	Updated (UTC)
docs	Ready	Preview, Comment	Feb 20, 2026 5:48am

[greptile-apps]

Greptile Summary

Fixed critical crash in terminal spawning by correcting the CSI handler callback parameter type for the DECRQM workaround.

Key changes:

• Updated registerCsiHandler callback params from { params: number[] } to (number | number[])[] in both ANSI and DEC mode handlers
• Changed access pattern from params.params[0] to params[0] with appropriate type assertion
• The bug was dormant since the workaround was added but triggered when OpenCode CLI sent mode-query escape sequences

Impact:

• Prevents Cannot read properties of undefined (reading '0') crash at TerminalSessionManager.ts:215
• Maintains existing DECRQM workaround functionality for Amp agent
• No behavioral changes, only corrects the type signature to match xterm.js API

Confidence Score: 5/5

• This PR is safe to merge with no risk
• The fix corrects a clear type error where the callback parameter signature didn't match the xterm.js API. The change is minimal (4 lines), well-documented in the PR description, and only affects the type annotation and property access pattern - no logic changes. The fix directly addresses a runtime crash with a straightforward correction.
• No files require special attention

Important Files Changed

Filename	Overview
src/renderer/terminal/TerminalSessionManager.ts	Fixed critical type error in CSI handler callback - corrected params type from object to array, preventing crash when OpenCode sends DECRQM sequences

_{Last reviewed commit: 91ab080}