docs: how-to for ignoring files (`.loreignore`) and view filters

Summary

On game-engine working copies, lore status --scan walks the entire tree — including build-artifact directories that will never be committed (Intermediate/, Saved/, DerivedDataCache/, Binaries/, embedded tool caches). There is currently no way to exclude paths from scanning: neither status --scan nor stage --scan exposes an ignore/exclude option, and config.toml has no ignore section (checked on 0.8.4+283).

A .loreignore file (or config-level ignore patterns) honored by status --scan / stage --scan would remove a large fixed cost from every scan-driven operation, and would also prevent runtime caches from being accidentally staged into history.

Measurements

Setup: UE 5.8 Lyra-derived project, Windows 10 / NTFS, lore 0.8.4+283, repository created with --use-shared-store. Tracked-relevant tree ≈ 12.4k files (Content/ 2,968 · Plugins/ 8,916 · Source/ 496 · Config/ 46); the working copy additionally holds several thousand files under Intermediate/, Saved/, Binaries/, DerivedDataCache/.

Scan	wall time
lore status --scan . (full tree, first run)	~21.8 s
lore status --scan . (repeat)	~18.1 s
lore status --scan Content Config Source Plugins <project>.uproject (scoped)	~1.4 s

Scoped and full scans report identical tracked-change sets on this tree (also verified positional args vs --targets file: identical results), so effectively the entire 17-20 s delta is spent walking never-committed build artifacts.

Why it matters

Editor integrations (e.g. source-control providers) and scripts commonly run scan-driven status before a check-in; on UE-sized projects that turns a 1-file submit into a tens-of-seconds operation unless every caller hand-maintains a scoped path list. An ignore mechanism puts that knowledge in one place, in the repository.

Ask

• .loreignore (gitignore-style patterns, repo-root) honored by status --scan and stage --scan, or equivalently an [ignore] section in config.toml.
• A --no-ignore escape hatch for the rare full-tree audit.

Happy to provide more measurements or test a preview build.