feat: add core HTTP client with plugin system and built-in plugins

Introduce a new package `@tdanks2000/api-core` that provides a shared HTTP client runtime for the api-wrappers organization. This foundational library includes:

- A plugin-based architecture with lifecycle hooks (setup, beforeRequest, afterResponse, onError, dispose)
- Built-in plugins for caching, retry logic, logging, and timeouts
- GraphQL support with automatic error handling
- Transport abstraction with a default fetch-based implementation
- Comprehensive TypeScript types and error classes (ApiError, RateLimitError, TimeoutError)
- Test suite covering all major components
- Documentation including migration guide and plugin authoring guide

The implementation enables consistent HTTP behavior across all API wrapper packages while maintaining backward compatibility with existing wrapper interfaces.

Author: TDanks2000

.gitignore

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+# dependencies (bun install)
+node_modules
+
+# output
+out
+dist
+*.tgz
+
+# code coverage
+coverage
+*.lcov
+
+# logs
+logs
+_.log
+report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# caches
+.eslintcache
+.cache
+*.tsbuildinfo
+
+# IntelliJ based IDEs
+.idea
+
+# Finder (MacOS) folder config
+.DS_Store
+
+**/.ai