housekeeper: unexport in-file-only BinaryNotice component

[stonexer]

What

Drop the export keyword from BinaryNotice in packages/server/src/components/artifactView.tsx. It stays a plain module-local function - no behavior change.

Why

BinaryNotice is a private presentational subcomponent rendered only within artifactView.tsx (3 in-file call sites). Nothing imports it, so the export leaked accidental module surface - the same class of cleanup as #146 (fmtBytes). Unlike a design-token/lib symbol, a component-local render helper has no public-API rationale to be exported.

Evidence

• Repo-wide rg '\bBinaryNotice\b' matches only artifactView.tsx (declaration + 3 uses); zero references in the daemon package or tests.
• No barrel re-export of artifactView (rg "export .* from .*artifactView" empty).
• Not accessed dynamically / via glob.

Checks

• pnpm -r typecheck green (server + daemon)
• pnpm --filter @loopany/server test green (645 passed, 3 skipped)