chore: upgrade the LangChain and LangGraph runtime

[tdpham2]

Summary

• Upgrade and exactly pin the LangChain/LangGraph base runtime compatibility unit.
• Remove pyppeteer and its Mermaid PNG renderer, leaving ChemGraph.visualize() ASCII-only.
• Remove obsolete headless Chrome packages from the Docker image while preserving uvicorn(..., ws="none") for streamable HTTP.
• Adapt the affected LangChain tool invocation and add visualization plus interrupt/resume regression coverage.
• Preserve async interrupt/resume behavior on Python 3.10 by explicitly restoring the runnable context for the multi-agent human-review node.
• Temporarily unpin legacy provider integrations in environment.yml so they resolve against LangChain 1.x; the provider family will be pinned in PR 3.

Pyppeteer is included in this PR because pyppeteer==2.0.0 requires websockets<11, while langgraph-sdk==0.4.2 requires websockets>=14,<16. Its only runtime use was the removed Mermaid PNG branch, so retaining it blocked this runtime upgrade.

Related issues

#130

Type of change

• Bug fix
• New feature
• Docs
• Chore / refactor / CI

How was this tested?

• ruff check .
• pytest tests/ -q -k "not tblite": 287 passed, 28 skipped, 2 deselected
• Focused migration suite: 56 passed
• Exact Python 3.10 astream interrupt/checkpoint/resume probe against the pinned runtime
• Clean editable installation followed by pip check
• Source distribution and wheel build
• Wheel installation and pip check in a second clean environment
• Repository scan confirming no pyppeteer or Mermaid references remain
• GitHub Actions passed across Python 3.10-3.13 on Linux, macOS, and Windows, including conda/MACE, extras, wheel-install, lint, and dependency-install matrices

Checklist

• Branched off the latest main and targets main
• PR is focused on a single logical change (split if it grew large)
• ruff check . passes
• pytest tests/ -k "not tblite" passes (plus extras tests if Academy/backends touched)
• Added/updated tests for the change
• Updated docs / README for any user-facing change (N/A: no docs or README references used the removed Mermaid renderer; the API docstring and repository guidance were updated)