fix(tests): resolve TypeScript errors in validation tests

- Cast unknown schemas to object when calling ajv.addSchema()
- Add non-null assertion for array access after length check
- Add type assertion for regex captured groups
- Add null coalescing for optional regex capture

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: ericyangpan

tests/validate/manifests.schema.test.ts

@@ -77,7 +77,7 @@ function loadBaseSchemas(ajv: ReturnType<typeof createAjv>, schemasDir: string)
       continue
     }
     const schema = readJsonFile(schemaPath)
-    ajv.addSchema(schema, name)
+    ajv.addSchema(schema as object, name)
   }
 }
 
@@ -99,7 +99,7 @@ function resolveRelativeRefs(obj: unknown, baseDir: string, ajv: ReturnType<type
       const refSchema = readJsonFile(refPath)
       const refId = path.basename(refPath)
       if (!ajv.getSchema(refId)) {
-        ajv.addSchema(refSchema, refId)
+        ajv.addSchema(refSchema as object, refId)
       }
       record.$ref = refId
     }

tests/validate/translations.structure.test.ts

@@ -131,14 +131,17 @@ function validateTranslationStructures(rootDir: string): string[] {
     structures.set(locale, getLocaleStructure(translationsDir, locale))
   }
 
-  const referenceLocale = locales[0]
+  const referenceLocale = locales[0]!
   const reference = structures.get(referenceLocale)
   if (!reference) return failures
 
   for (let i = 1; i < locales.length; i++) {
-    const locale = locales[i]
+    const locale = locales[i]!
     const current = structures.get(locale)
-    if (!current) continue
+    if (!current) {
+      failures.push(`[${locale}] structure not found`)
+      continue
+    }
 
     const fileDiff = diffSets(new Set(reference.fileList), new Set(current.fileList))
     if (fileDiff.onlyInA.length > 0 || fileDiff.onlyInB.length > 0) {

tests/validate/typesAlignment.test.ts

@@ -88,9 +88,9 @@ function parseTypeScriptInterface(
     const trimmed = line.trim()
     const fieldMatch = trimmed.match(/^(\w+)(\?)?\s*:\s*(.+)$/)
     if (fieldMatch) {
-      const name = fieldMatch[1]
+      const name = fieldMatch[1] as string
       const optional = fieldMatch[2] === '?'
-      const type = fieldMatch[3].trim()
+      const type = fieldMatch[3]?.trim() ?? 'unknown'
       fields[name] = { optional, type }
     }
   }