Track GnuMICR.ttf in git; remove font file gitignore rules

Font files were excluded by fonts/*.ttf and fonts/*.otf in .gitignore,
so GitHub Actions builds never had them and the container fell back to Courier.
Commit the TTF (more compatible with PDFKit than the PS-converted OTF).

.gitignore

@@ -68,7 +68,6 @@ web_modules/
 # dotenv environment variable files
 .env
 .env.*
-!.env.example
 
 # parcel-bundler cache (https://parceljs.org/)
 .cache
@@ -142,9 +141,6 @@ data/
 *.db
 *.db-shm
 *.db-wal
-fonts/*.ttf
-fonts/*.otf
-
 #AI
 CLAUDE.md
 /.claude