Perf: memoize inline locations and gate editor search

[GitAddRemote]

Summary

• Gate new-row item search to Editor Mode to avoid unnecessary catalog calls in standard view.
• Add memoized location filtering hook and wire inline rows to use it, reducing per-row recomputation while keeping focus/error behavior.
• Virtualization deferred due to focus/a11y/state complexity; tracked in Investigate Editor Mode virtualization with focus/a11y support #85.

Testing

• pnpm --filter frontend lint
• pnpm --filter frontend build
• pnpm --filter frontend test -- --runTestsByPath frontend/src/pages/Inventory.editor-mode.test.tsx