chore: neutral report path and plain punctuation

The markdown report wrote to a directory named after the tooling that
happened to produce it. It takes --report-dir now, defaulting to
reports/, so nothing in the tree names anything but the project.

Em-dashes replaced throughout the sources and tests, rephrased rather
than swapped for a comma where the dash carried an apposition.

scripts/packextras.py

@@ -148,7 +148,7 @@ def _agnostic_scan_extras(
     """
     extras: list[dict] = []
     files_db = db.get("files", {})
-    # Third pass: agnostic scan — for filename-agnostic cores, include all
+    # Third pass: the agnostic scan. For filename-agnostic cores, include all
     # DB files matching the system path prefix and size criteria.
     for emu_name, profile in sorted(profiles.items()):
         if profile.get("type") in ("launcher", "alias"):