Architecture budgets

The scripts/check-architecture.mjs checker reports the source-file count, total physical line count, largest source files, and the >500, >1000, and >2000 LOC threshold counts for tracked source under apps/, packages/, crates/, and scripts/. Generated output, dependency trees, and build directories are excluded.

The checker enforces these limits:

• apps/desktop/electron/main/index.ts is at most 1500 LOC.
• apps/desktop/src/stores/app-store.ts is at most 1000 LOC.
• A newly added ordinary TypeScript or TSX source file is at most 800 LOC, unless it has a reasoned entry under typescript in allowlist.json.
• Every Rust source file above 1000 LOC has a reasoned entry under rust in allowlist.json.

The Rust entries currently document legacy modules that were outside the follow-up split scope. New Rust domain files are expected to remain below the limit. An allowlist entry records an explicit debt boundary; it does not raise the general limit for future files.