feat(coverage): exclude index.ts from coverage requirements

Index.ts is a re-export module with no testable logic. Excluding from
coverage calculation to focus on actual implementation files.

- Add src/index.ts to coverage exclude list
- Add c8 ignore comments to index.ts for documentation
- Coverage now accurately reflects testable code
- Current baseline: 74.65% statements (target: 97%)

The index-exports.test.mts validates the public API surface.

Author: jdalton

.config/vitest.coverage.config.mts

@@ -26,6 +26,7 @@ export const baseCoverageConfig: CoverageOptions = {
     '**/*.mjs',
     '**/*.cjs',
     'src/types.ts',
+    'src/index.ts',
     'perf/**',
     // Explicit root-level exclusions
     '/scripts/**',

src/index.ts

@@ -3,6 +3,7 @@
  * Provides the SocketSdk class and utility functions for Socket security analysis API interactions.
  */
 
+/* c8 ignore start - Re-export module, no testable logic */
 // Import from our modules.
 import { DEFAULT_USER_AGENT, httpAgentNames, publicPolicy } from './constants'
 import {
@@ -134,3 +135,4 @@ export {
 
 // Re-export constants.
 export { DEFAULT_USER_AGENT, httpAgentNames, publicPolicy }
+/* c8 ignore stop */