v0.4.28

Fixes

• #498 OpenCode install bugs (3 sub-issues)
  • opencode.json now written to .opencode/opencode.json instead of project root — consistent with OpenCode's config directory
  • All intermediate temp files (.graphify_detect.json, .graphify_extract.json, etc.) in skill-opencode.md now correctly use graphify-out/ prefix instead of leaking to project root
  • Added missing --wiki step (Step 6b) to skill-opencode.md, matching all other platform skills