feat: list unsourceable launcher names apart

A launcher name that a reader's profile entry declares unsourceable is
no file left to find. Its row carries the reason and both reports
print it under its own count, never mixed with the names to acquire.

scripts/cross_reference.py

@@ -1204,6 +1204,16 @@ def launcher_reads_not_held(
                 "source_ref": str(record.get("source_ref", "")),
                 "profiles": readers,
             }
+            # A name a reader's entry declares unsourceable is no gap: its
+            # row carries the reason and is counted apart.
+            unsourceable = {
+                str(n).rsplit("/", 1)[-1]: str(entry["unsourceable"])
+                for key in readers
+                for entry in profiles[key].get("files") or []
+                if entry.get("unsourceable")
+                for n in (entry.get("name"), *(entry.get("aliases") or []))
+                if n
+            }
             for name in names:
                 found = holder.held(name)
                 if found and (found[1] or folds):
@@ -1219,6 +1229,9 @@ def launcher_reads_not_held(
                     }
                     if found:
                         row["held_as"] = found[0]
+                reason = unsourceable.get(name.rsplit("/", 1)[-1])
+                if reason and "unsourceable" not in row:
+                    row["unsourceable"] = reason
                 if reader["emulator"] not in row["emulators"]:
                     row["emulators"].append(reader["emulator"])
                 if reader not in row["readers"]:
@@ -1228,7 +1241,13 @@ def launcher_reads_not_held(
 
 
 def print_launcher_reads(rows: list[dict]) -> None:
-    """The launcher reads gap category, after the profile gaps."""
+    """The launcher reads gap category, after the profile gaps.
+
+    A name its reader declares unsourceable is listed apart, with the
+    reason: it is no file left to find.
+    """
+    unsourceable = [r for r in rows if r.get("unsourceable")]
+    rows = [r for r in rows if not r.get("unsourceable")]
     platforms = sorted({r["platform"] for r in rows})
     noun = "platform" if len(platforms) == 1 else "platforms"
     print(f"\nLauncher reads, not held: {len(rows)} names across {len(platforms)} {noun}")
@@ -1242,6 +1261,19 @@ def print_launcher_reads(rows: list[dict]) -> None:
                 f"    {row['name']} [{', '.join(row['emulators'])}, {first['kind']}, "
                 f"{first['source_ref']}]{more}{casing}"
             )
+    if not unsourceable:
+        return
+    platforms = sorted({r["platform"] for r in unsourceable})
+    noun = "platform" if len(platforms) == 1 else "platforms"
+    print(
+        f"\nLauncher reads, unsourceable: {len(unsourceable)} names "
+        f"across {len(platforms)} {noun}"
+    )
+    for row in unsourceable:
+        print(
+            f"    {row['platform']}: {row['name']} [{', '.join(row['emulators'])}, "
+            f"{row['readers'][0]['source_ref']}]: {row['unsourceable']}"
+        )
 
 
 def cross_reference(