feat(source2): lock dark mode, sans-serif typography, and all recent updates

docs/vibe-coding/opencode-ide.md

@@ -0,0 +1,10 @@
+# OpenCode
+
+OpenCode reads a root-level `AGENTS.md` natively, the same convention Claude Code
+uses for `CLAUDE.md` — this kit's `AGENTS.md` is picked up as-is with no pointer file
+needed.
+
+- Confirm it's loaded via OpenCode's session/context inspector before relying on it.
+- If OpenCode is used alongside Claude Code on the same repo, keep `CLAUDE.md` as the
+  thin `@AGENTS.md` import (already set up in this kit) so both tools read one source
+  of truth.