Rename sf hamilton to apache hamilton

[skrawcz]

Summary

Rename all sf-hamilton references to apache-hamilton across the repository.

All 5 Hamilton packages were already migrated to flit + apache-hamilton prefix in their pyproject.toml files, but ~250 files still referenced the old sf-hamilton name in
documentation, examples, error messages, CI workflows, and other places. This PR updates them all for consistency.

What changed

• Python source (hamilton/plugins/h_*.py, graph.py, cli, etc.) — error messages now say pip install apache-hamilton[...]
• Documentation (docs/, README.md, package READMEs) — install instructions updated
• Examples (~170 files) — requirements.txt, .py, .ipynb all reference apache-hamilton
• CI workflows — PyPI version checks and environment names updated
• VSCode extension — install commands updated
• UI frontend — SDK install instruction updated
• pyproject.toml — lsp/sdk/ui extras still point to sf-hamilton-* (only dev prereleases exist on PyPI for the apache-prefixed subpackages); TODO comments mark
  these for update once stable versions are published
• ui/backend/pyproject.toml — dependency changed from sf-hamilton to apache-hamilton (stable 1.90.0 exists on PyPI)
• Disable ddtrace pytest plugin — ddtrace auto-registers a pytest plugin that spawns background threads preventing clean process exit after the test suite. Disabling it
  fixes the test suite hang. Hamilton's own DDOGTracer tests are unaffected.
• scripts/find_hanging_tests.sh — new utility that runs each test file individually with a timeout to identify tests that prevent pytest from exiting

What did NOT change

• Import names (e.g., import hamilton, from hamilton.contrib import ...) — unchanged
• sf-hamilton-redirect/ — intentionally references both names (it's the PyPI redirect package)
• scripts/generate_announce_email.py — sf-hamilton- tag matching for historical changelog
• scripts/README.md — documents the sf-hamilton redirect workflow

Test plan

• uv sync resolves cleanly
• Full test suite passes: 1415 passed, 3 skipped, 2 xpassed (63s, clean exit)
• Grep audit: only intentional sf-hamilton references remain (3 files)
• Example smoke tests in fresh venvs (hello_world, data_quality, pandas/materialization, plotly/visualization)
• apache-hamilton[visualization] extra resolves from PyPI

Checklist

• PR has an informative and human-readable title (this will be pulled into the release notes)
• Changes are limited to a single goal (no scope creep)
• Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future TODOs are captured in comments
• Project documentation has been updated if adding/changing functionality.

[skrawcz]

revert this one?

[skrawcz]

hmm maybe we just fix forward...