CLI misdetects Android/Termux environment as Linux

[equitablememe]

Description

Android/Termux environments are currently treated as standard Linux in the CLI launcher.

This can lead to runtime failures due to incompatible binaries.

A detection check should be added to identify Android/Termux environments early and exit with a clear unsupported message.

Plugins

No response

OpenCode version

No response

Steps to reproduce

1. Run the CLI in an Android/Termux environment
2. Observe that the system treats it as standard Linux
3. Attempt to execute CLI commands
4. Notice failures or incompatible binary behavior

Screenshot and/or share link

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Operating System

No response

Terminal

No response

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Termux support 🙏 #961: Termux support request (open)
• Android Termux bug #10550: Android Termux bug (open)
• OpenCode binary fails to run natively on Termux / Android aarch64 (wrong interpreter + non‑PIE executable) #10504: OpenCode binary fails to run natively on Termux / Android aarch64 - wrong interpreter + non-PIE executable (open)
• Android/Termux install fails: postinstall requires missing package opencode-android-arm64 #12515: Android/Termux install fails: postinstall requires missing package opencode-android-arm64 (open)

Please review the above issues to see if your report is already covered. If it is, consider adding a comment there instead. If your issue is distinct, please clarify what makes it different.

[equitablememe]

Description
Android/Termux environments are currently treated as standard Linux in the CLI launcher, which can result in runtime failures due to incompatible binaries.
Because Termux runs in a constrained Android environment, certain assumptions made for standard Linux systems (e.g., binary compatibility, filesystem layout) do not hold.
A detection check should be added early in the launcher to identify Android/Termux environments and exit with a clear unsupported platform message.
Steps to Reproduce
Run the CLI within a Termux (Android) environment
Observe that the environment is detected as standard Linux
Attempt to execute CLI commands
Encounter runtime failures or incompatible binary execution
Expected Behavior
The CLI should detect Android/Termux environments early and exit with a clear message indicating that the platform is not yet supported.
Actual Behavior
The CLI proceeds as if running on standard Linux, which may lead to failures due to incompatible binaries.
Environment
OS: Android (Termux)
Terminal: Termux
Notes
Early environment detection would prevent unnecessary execution attempts and provide clearer feedback to users, improving overall reliability and user experience.