fix: curl install URL returns HTML instead of shell script

[dev-punia-altimate]

Problem

The upgradeCurl() function in packages/opencode/src/installation/index.ts:37 fetches https://altimate.ai/install and pipes the response to bash. This URL returns the website HTML, not a shell script.

Tested both domains:

• https://altimate.ai/install → HTTP 302 → website HTML

Doesn't serves the install script. The only working URL is:

https://raw.githubusercontent.com/AltimateAI/altimate-code/main/install

Impact

Any user running altimate-code upgrade with method=curl gets a bash syntax error. This affects all curl-installed users on macOS and Linux.

Evidence

Install matrix run: https://github.com/AltimateAI/altimate-qa/actions/runs/23295037235

curl install failed: exit=1
bash: line 1: syntax error near unexpected token `<'

Fix needed

Either:

1. Configure altimate.sh/install (or altimate.ai/install) to serve the shell script from the repo's install file
2. Or update the code to use the GitHub raw URL as primary source

PR #274 adds a fallback to the GitHub raw URL as a workaround.