feat: Merge isohash functionality into smarthash for cross-environment hash support

- Updated test files to use new tapbundle import from @git.zone/tstest.
- Created a new plan for merging isohash into smarthash, detailing objectives and implementation steps.
- Added browser-specific tests for SHA256 hashing functions in test/test.browser.ts.
- Implemented browser-compatible hashing functions in ts_web/index.ts using Web Crypto API.
- Introduced plugins for environment detection and JSON handling in ts_web/plugins.ts.
- Ensured that existing smarthash functionality remains intact and consistent across environments.

test/test.browser.ts

@@ -0,0 +1,65 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as smarthash from '../ts_web/index.js';
+
+tap.test('sha256FromString should work in browser environment', async () => {
+  const testHash = await smarthash.sha256FromString('test');
+  const testHash2 = await smarthash.sha256FromString('testString');
+  const testHash3 = await smarthash.sha256FromString('test');
+  
+  expect(testHash).toEqual(testHash3);
+  expect(testHash).not.toEqual(testHash2);
+  expect(testHash).toBeTypeofString();
+  expect(testHash).toHaveLength(64); // SHA256 hash is 64 hex characters
+});
+
+tap.test('sha256FromBuffer should work with Uint8Array in browser', async () => {
+  const encoder = new TextEncoder();
+  const buffer = encoder.encode('test');
+  
+  const hashFromBuffer = await smarthash.sha256FromBuffer(buffer);
+  const hashFromString = await smarthash.sha256FromString('test');
+  
+  expect(hashFromBuffer).toEqual(hashFromString);
+});
+
+tap.test('sha265FromObject should produce reproducible hashes', async () => {
+  const hash1 = await smarthash.sha265FromObject({
+    hithere: 1,
+    wow: 'two',
+  });
+
+  const hash2 = await smarthash.sha265FromObject({
+    wow: 'two',
+    hithere: 1,
+  });
+
+  const hash3 = await smarthash.sha265FromObject({
+    wow: 'twoe',
+    hithere: 1,
+  });
+  
+  expect(hash1).toEqual(hash2);
+  expect(hash1).not.toEqual(hash3);
+});
+
+tap.test('sha256FromStringSync should throw in browser environment', async () => {
+  expect(() => {
+    smarthash.sha256FromStringSync('test');
+  }).toThrow();
+});
+
+tap.test('sha256FromStream should throw in browser environment', async () => {
+  expect(() => {
+    smarthash.sha256FromStream(null);
+  }).toThrow();
+});
+
+tap.test('sha256FromFile should throw in browser environment', async () => {
+  await expect(smarthash.sha256FromFile('./test.txt')).rejects.toThrow();
+});
+
+tap.test('md5FromString should throw in browser environment', async () => {
+  await expect(smarthash.md5FromString('test')).rejects.toThrow();
+});
+
+export default tap.start();