fix(types): tighten dict generics and rich types

[CoderDeltaLAN]

• fix(types): add concrete generics and fix Text.assemble usage (mypy clean)
• fix(types): specify dict generics and clean Text.assemble; fix counts init (mypy green)
• ci: trigger checks for PR fix(types): mypy green #27
• fix(types): concrete dict generics; clean annotations; ignore arg-type on Text.assemble
• fix(types): concrete generics (dict[str,int]/dict[str,str]); fix Text.assemble; mypy green