feat: add killturn to general meta and update related tests

- Introduced a new meta property `killturn` to the GeneralMeta interface.
- Implemented a function `readMetaNumber` to handle the retrieval of numeric values from meta.
- Updated the `mapGeneralRow` function to ensure `killturn` is required and properly handled.
- Modified various tests to include the `killturn` property in the general's meta data.
- Adjusted related action files to utilize the new GeneralMeta type for better type safety.
- Ensured backward compatibility by updating existing test cases across multiple scenarios.

app/game-engine/test/npcNationTechResearch.test.ts

@@ -30,7 +30,7 @@ const createNpcGeneral = (
         specialWar: null,
     },
     triggerState: { flags: {}, counters: {}, modifiers: {}, meta: {} },
-    meta: {},
+    meta: { killturn: 800 },
     officerLevel,
     experience: 0,
     dedication: 0,