Remove duplicate input validation tests from result.test.mts

Removed redundant tests that verify input validation already covered in core methods:
- tryFromString non-string input validation
- tryFromObject non-object input validation
- tryFromJSON non-string input validation
- tryParseString non-string input validation

These Result wrapper methods delegate to core methods tested in json-export.test.mts and package-url.test.mts.

Author: jdalton

test/result.test.mts

@@ -246,15 +246,6 @@ describe('PackageURL Result methods', () => {
       expect(result.isErr()).toBe(true)
       expect((result as Err<Error>).error).toBeInstanceOf(Error)
     })
-
-    it('should return Err for non-string input', () => {
-      const result = PackageURL.tryFromString(123)
-
-      expect(result.isErr()).toBe(true)
-      expect((result as Err<Error>).error.message).toContain(
-        'purl string argument is required',
-      )
-    })
   })
 
   describe('tryFromObject', () => {
@@ -276,15 +267,6 @@ describe('PackageURL Result methods', () => {
       expect(result.isErr()).toBe(true)
       expect((result as Err<Error>).error).toBeInstanceOf(Error)
     })
-
-    it('should return Err for non-object input', () => {
-      const result = PackageURL.tryFromObject('not an object')
-
-      expect(result.isErr()).toBe(true)
-      expect((result as Err<Error>).error.message).toContain(
-        'Object argument is required',
-      )
-    })
   })
 
   describe('tryFromJSON', () => {
@@ -308,15 +290,6 @@ describe('PackageURL Result methods', () => {
       )
     })
 
-    it('should return Err for non-string input', () => {
-      const result = PackageURL.tryFromJSON(123)
-
-      expect(result.isErr()).toBe(true)
-      expect((result as Err<Error>).error.message).toContain(
-        'JSON string argument is required',
-      )
-    })
-
     it('should return Err for valid JSON with invalid purl data', () => {
       const json = '{"type":"","name":"lodash"}'
       const result = PackageURL.tryFromJSON(json)
@@ -347,15 +320,6 @@ describe('PackageURL Result methods', () => {
       expect(result.isErr()).toBe(true)
       expect((result as Err<Error>).error).toBeInstanceOf(Error)
     })
-
-    it('should return Err for non-string input', () => {
-      const result = PackageURL.tryParseString(null)
-
-      expect(result.isErr()).toBe(true)
-      expect((result as Err<Error>).error.message).toContain(
-        'purl string argument is required',
-      )
-    })
   })
 
   describe('functional composition', () => {