[BUG] Binary name collision: `opencode` vs `OpenCode` on case-insensitive filesystems

[jerome-benoit]

Description

Commit 96975ef renamed the desktop binary from "OpenCode Desktop" to "OpenCode", causing collision with CLI binary opencode on case-insensitive filesystems (macOS/Windows default).

Root Cause

Commit: 96975ef8d608b210cffd4befeaad5ce0db66e4de (Dec 14, 2025)
File: packages/tauri/src-tauri/tauri.conf.json

- "mainBinaryName": "OpenCode Desktop",
+ "mainBinaryName": "OpenCode",

Problem

On case-insensitive filesystems, OpenCode and opencode are treated as the same file:

• Desktop binary overwrites CLI binary (or vice versa)
• Cannot install both in same directory
• Blocks Nix packaging (#9032) and breaks existing installations (#8998)

Cross-Platform Binary Naming

Standard conventions prohibit:

• ❌ Mixed case (filesystem collision)
• ❌ Spaces (breaks shell scripting)
• ❌ Underscores (library naming conflicts)

Recommended:

• ✅ Lowercase with hyphens: opencode-desktop

Solution

Rename desktop binary to opencode-desktop (matches existing package naming conventions).

References

• Breaking commit: 96975ef
• Discussion: #9032 (comment r2700886644)
• Related: #7666 (Windows UX confusion - different issue)