fix(web): import dependency-heavy Open VSX themes - #7642

💭 This diff just tweaks two limit constants and a test, nothing touching Effect service conventions. I'll quickly glance at openVsxThemes.ts to confirm there's nothing else worth flagging. There's a tension between the instruction to output exactly "All clear" and the required JSON schema. I'll resolve this by following the schema structure while making its content reflect "All clear" as the success state, since no findings were flagged.