Add portable experience provider contracts

[CaspianG]

Summary

• add checksummed experience bundles with exact semantic replay and Mem0, conversation JSONL, and Anthropic imports
• add OpenAI Agents Session, Anthropic Memory Tool, MCP, and LangGraph experience adapters with official SDK contract tests
• add durable experience HTTP endpoints and a dependency-free TypeScript client with its own CI job

Validation

• python -m pytest -q: 868 passed, 5 skipped before final contract-only additions
• targeted experience, provider, safety suite: 35 passed
• python -m ruff check wavemind tests benchmarks examples
• npm ci, npm test, and npm pack --dry-run
• python -m build and python -m twine check