Release Python SDK v1.0.1 public sync

[ethanj]

Summary

Public release sync for the Python SDK v1.0.1 line.

This PR updates the public Python SDK mirror with the launch-ready package metadata, provider additions, docs, and release hygiene needed before publishing the next Python package.

Rollup

• Bumps atomicmemory from 1.0.0 to 1.0.1, updates uv.lock, and records the release in CHANGELOG.md.
• Adds Hindsight provider parity, including sync/async providers, config, HTTP client, mappers, registry exports, and tests.
• Updates AtomicMemory client/provider behavior and related test coverage.
• Adds public governance docs: CONTRIBUTING.md, CODE_OF_CONDUCT.md, and SECURITY.md.
• Adds public GitHub issue templates and pull request template for launch readiness.
• Adds launch README and public roadmap content.

Verification

• Public CI: ci (3.10) passed.
• Public CI: ci (3.11) passed.
• Public CI: ci (3.12) passed.
• Public CI: ci (3.13) passed.
• Package release prep included dependency sync, tests, lint, and package build.