PR-001: Domain Model v1.0 — compile-only, zero dependencies

- @landvex/domain package with TypeScript strict mode
- 3 Aggregate Roots: FieldSession, Mission, DecisionCase
- Branded IDs, Value Objects, Domain Events, Invariants
- 19 unit tests for IDs, FieldSession, DecisionCase
- Zero runtime dependencies (only TypeScript + jest for tests)
- Separates Entity / Value Object / Aggregate Root
- README documents Three Rules of the domain

Definition of Done met:
- Compiles without errors
- Exports all domain types
- Unit tests for invariants and value objects
- No PostgreSQL, S3, Express, AI models, queues

packages/domain/tsconfig.json

@@ -0,0 +1,29 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "commonjs",
+    "lib": ["ES2022"],
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "strictFunctionTypes": true,
+    "strictBindCallApply": true,
+    "strictPropertyInitialization": true,
+    "noImplicitThis": true,
+    "alwaysStrict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist", "**/*.test.ts"]
+}