launch-suppressor: apply lands only its own records; tests pin late hiding, the rating line, linear suppression and a named observer sensor

Command: the batch carries ExpectUnchanged, so CultCache lands it onto the file as it is. A plain commit re-encoded every record through today's types (two sensors lost a retired key-7 payload and gained a trailing nil, LRMM72 and GT 3K gained a trailing nil); this one leaves every record it did not author byte-identical. A conflicting writer now fails the apply instead of being overwritten.

Tests: the mild baffle stores exactly flash x Factor and pays exactly its predicted heat for the first 30 launches of a 300 flash or 8 of a 1000 flash, then is either hidden or bright; the rating is pinned to half a kelvin either side at three heat-sink qualities; suppression and heat are checked at six flash strengths; the observer fits the named sensor 'not if i see you first'; the command test widens every payload and checks apply leaves all other records byte-identical.

This commit's GameData/Aetheria.cc pointer is the previous apply's output; the regenerated catalog follows in its own commit. Not built or run at this commit yet.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/AetherDb/Program.cs

@@ -2357,8 +2357,11 @@ public static class Program
         }
 
         foreach (var design in designs) CultRecordRefs.Validate(design);
-        db.Cache.Commit(batch =>
+        // ExpectUnchanged lands the batch onto the file as it is: every other record keeps the bytes it has, where a plain
+        // commit would re-encode the whole catalog through today's types.
+        if (!db.Cache.Commit(batch =>
         {
+            batch.ExpectUnchanged();
             var keys = new Dictionary<GearData, CultRecordKey>();
             foreach (var design in designs) keys[design] = batch.Upsert(typeof(GearData), design);
             foreach (var (design, name, maker, description) in products)
@@ -2373,7 +2376,8 @@ public static class Program
                     Roles = design.Roles.Select(r => new ProductRole { Role = r.Name, Mean = mean, StandardDeviation = dev }).ToList(),
                 });
             }
-        });
+        }))
+            throw new InvalidOperationException("The catalog changed while the launch suppressors were being authored; nothing was written. Run it again.");
         Console.WriteLine($"\nAuthored 2 designs and {products.Length} products in Aetheria.cc");
         return 0;
     }