⚡ Add explicit type field to all SDK clients (#175)

## Summary

Adds the `type` field to all SDK clients that send screenshot image
data. This completes the performance optimization from #174 by ensuring
all clients benefit from O(1) type detection on the server.

## Changes

| SDK | File | Type Sent |
|-----|------|-----------|
| Full SDK | `src/sdk/index.js` | `type: 'base64'` |
| Vitest | `clients/vitest/src/setup.js` | `type: 'file-path'` |
| Ruby | `clients/ruby/lib/vizzly.rb` | `type: 'base64'` |
| Swift | `clients/swift/.../VizzlyClient.swift` | `type: 'base64'` |

**No changes needed:**
- **Core client** (`src/client/index.js`) - Already updated in #174
- **Static-site** - Uses core client SDK
- **Storybook** - Uses core client SDK
- **Ember** - Different architecture (sends selector, server takes
screenshot)

## Packages to Release

After merging, the following packages need new releases:

| Package | Registry | Notes |
|---------|----------|-------|
| `@vizzly-testing/cli` | npm | Main CLI package |
| `@vizzly-testing/vitest` | npm | Vitest plugin |
| `vizzly` | RubyGems | Ruby gem |
| `Vizzly` | Swift Package Manager | Swift package |

## Test Plan

- [x] All 1751 tests pass
- [x] Backwards compatible (server falls back to detection if `type`
missing)

Author: Robdel12

clients/ruby/lib/vizzly.rb

@@ -55,6 +55,7 @@ def screenshot(name, image_data, options = {})
       payload = {
         name: name,
         image: image_base64,
+        type: 'base64',
         buildId: ENV.fetch('VIZZLY_BUILD_ID', nil),
         threshold: options[:threshold] || 0,
         fullPage: options[:full_page] || false,

clients/ruby/test/integration_test.rb

@@ -39,8 +39,9 @@ def test_screenshot_with_running_server
     result = Vizzly.screenshot('test-screenshot', image_data,
                                properties: { browser: 'chrome', viewport: { width: 1920, height: 1080 } })
 
-    assert result
-    assert_equal true, result['success']
+    assert result, 'Expected result to be non-nil'
+    # TDD mode returns status: 'new' for first screenshot, 'match' for subsequent
+    assert %w[new match].include?(result['status']), "Expected status 'new' or 'match', got: #{result['status']}"
   end
 
   def test_screenshot_with_auto_discovery
@@ -57,8 +58,9 @@ def test_screenshot_with_auto_discovery
     image_data = create_test_png
     result = client.screenshot('auto-discovered', image_data)
 
-    assert result
-    assert_equal true, result['success']
+    assert result, 'Expected result to be non-nil'
+    # TDD mode returns status: 'new' for first screenshot, 'match' for subsequent
+    assert %w[new match].include?(result['status']), "Expected status 'new' or 'match', got: #{result['status']}"
   end
 
   private

clients/swift/Sources/Vizzly/VizzlyClient.swift

@@ -79,6 +79,7 @@ public final class VizzlyClient {
         var payload: [String: Any] = [
             "name": name,
             "image": imageBase64,
+            "type": "base64",
             "threshold": threshold,
             "fullPage": fullPage
         ]

clients/vitest/src/setup.js

@@ -60,6 +60,7 @@ async function toMatchScreenshot(element, name, options = {}) {
       body: JSON.stringify({
         name: screenshotName,
         image: screenshotPath, // Send file path directly
+        type: 'file-path',
         buildId: buildId || null,
         threshold,
         fullPage,

src/sdk/index.js

@@ -252,6 +252,7 @@ export class VizzlySDK extends EventEmitter {
       buildId,
       name,
       image: imageBase64,
+      type: 'base64',
       properties: options.properties || {},
     };