feat(sdk): monorepo repository to add new otel plugin package

[SilanHe]

Issue #, if available:

Description of changes:

Monorepo Restructure

The repo was converted from a single-package layout to a monorepo with a packages/ directory:

• Core SDK moved from the repo root (src/, tests/, examples/, pyproject.toml) into packages/aws-durable-execution-sdk-python/
• All source, tests, and examples were relocated (no content changes, just path moves)
• I moved all hatch env "testing" scripts to the root pyproject.toml and only left the build/publishing artifacts in the per package pyproject.toml. Working environments are defined in root pyproject.toml.

New Package: OpenTelemetry Instrumentation

A new package was added at packages/aws-durable-execution-sdk-python-otel/ (v0.1.0):

CI & Workflow Updates

• ci.yml — Loops over all packages/*/ directories for format checks, type checking, tests, and builds
• ci-checks.sh — Iterates over a PACKAGES array instead of running checks at the repo root
• pypi-publish.yml — Uses a matrix strategy to build and publish each package independently; per-package artifact names
• sync-package.yml — Deleted (no longer needed)
• deploy-examples.yml / integration-tests.yml — Minor path adjustments

Documentation

File	Change
CONTRIBUTING.md	Updated with monorepo structure overview; instructions to cd into package dirs before running hatch
RELEASING.md (new)	Release process: per-package versioning, tagging convention (sdk-vX.Y.Z, otel-vX.Y.Z), PyPI publishing flow, release notes format, pre-publish checklist
Core SDK README.md (new)	Package-level README inside the moved package directory

Misc

• .gitignore — Relaxed example build/zip patterns from root-anchored to relative (works with nested layout)

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[SilanHe]

I haven't actually tested this one but it looks quite reasonable. I had to work a little more closely with AI on this one.

[zhongkechen]

This wouldn't be practically doable when we have more packages (e.g. testing, etc) in this repo and we want to release all of them. And also the version dependency becomes less obvious, e.g. otel-0.3.0 requires sdk-1.6.0+ and a future version otel-0.4.0 requires sdk-1.7.0+.

[SilanHe]

For the tags, this is the best approach we've got. At the moment, with the number of packages we have this is currently doable. We can re-evaluate if we exceed tag size limits. We can always only bump and release one package at a time.

For the dependency tree, the source of truth should be the pyproject.toml for the package.

[zhongkechen]

linting and tests failed.

[SilanHe]

linting and tests failed.

Ah sorry, I was still working through the different worklows, there was an issue with a workflow which would check out the testing sdk into the root. Then the root testing scripts would pick up the testing sdk pyproject.toml