fix(demo): install coordinode-embedded from PyPI wheel, drop rustup/Rust build

[polaz]

Problem

All 4 Colab notebooks installed coordinode-embedded by:

1. Installing Rust via rustup (~2 min)
2. Installing maturin (~30 sec)
3. Building coordinode-embedded from git source (~5 min)

Total: ~8 minutes of compilation on every new Colab runtime.

Fix

Replace the entire rustup/Rust/maturin/protoc block with a single pip install coordinode-embedded from PyPI. The release workflow publishes pre-built manylinux wheels for Linux x86_64 (which is what Colab runs), so installation takes ~30 sec.

Also updated README timing note and markdown descriptions in all 4 notebooks.

[coderabbitai]

📝 Walkthrough

Summary by CodeRabbit

• Documentation
  • Updated Google Colab setup instructions across README and demo notebooks. Pre-built dependency installation now completes in ~30 seconds on first run (versus prior ~5-8 minutes), with instant subsequent runs. Installation process simplified.

Walkthrough

This PR updates the README and four demo notebooks to reflect that Google Colab now installs coordinode-embedded via pre-built PyPI wheels (~30 sec) rather than building from source (~5–8 min), removing Rust toolchain, protoc, and maturin build steps and replacing them with a simple conditional pip install.

Changes

Colab Setup Simplification

Layer / File(s)	Summary
Documentation Update README.md	Colab "first cell" note now states installation uses pre-built wheels (~30 sec) instead of source build (~8 min).
Notebook Dependency Installation demo/notebooks/00_seed_data.ipynb, demo/notebooks/01_llama_index_property_graph.ipynb, demo/notebooks/02_langchain_graph_chain.ipynb, demo/notebooks/03_langgraph_agent.ipynb	Colab setup cells replace Rust/protoc/maturin build logic with a unified pkgs list and single pip install call; conditionally prepends coordinode-embedded when in Colab without a COORDINODE_ADDR environment variable.
Notebook Environment Documentation demo/notebooks/00_seed_data.ipynb, demo/notebooks/01_llama_index_property_graph.ipynb, demo/notebooks/02_langchain_graph_chain.ipynb, demo/notebooks/03_langgraph_agent.ipynb	Opening markdown sections are updated to describe pre-built wheel installation (~30 sec) instead of source compilation (~5–8 min); minor comment/wording adjustments in embedded-mode adapter and connection sections.
Notebook Formatting & Cleanup demo/notebooks/00_seed_data.ipynb, demo/notebooks/02_langchain_graph_chain.ipynb, demo/notebooks/03_langgraph_agent.ipynb	Markdown headers are reformatted (e.g., step numbering); verification output display adjusted; cleanup calls client.close() instead of graph.close().

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• docs: add Try It in Google Colab section to README #62: Modifies README Colab instructions and demo notebook setup, directly related to the timing and install behavior of coordinode-embedded in Google Colab environments.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'fix(demo): install coordinode-embedded from PyPI wheel, drop rustup/Rust build' accurately summarizes the main change: replacing Rust compilation with PyPI pre-built wheels for faster Colab setup.
Description check	✅ Passed	The description clearly explains the problem (8 minutes of compilation), the fix (pip install from PyPI wheels), and its impact (~30 second installation), directly relating to all changeset modifications.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/#63-pypi-install-notebooks

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
1 Accepted issue

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@demo/notebooks/03_langgraph_agent.ipynb`:
- Around line 30-42: Restore the git-pinned SDK spec used for Colab to avoid
proto mismatches: introduce a variable named _coordinode_spec that selects the
git+https URL with the specific commit SHA when IN_COLAB and "coordinode"
otherwise, replace the plain "coordinode" entry in the pkgs list with
_coordinode_spec, and ensure subprocess.run (the pip install call that consumes
pkgs) installs the _coordinode_spec and still prefixes with
"coordinode-embedded" when IN_COLAB as before.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 9030cff1-3976-4873-a014-7266377f89e7

📥 Commits

Reviewing files that changed from the base of the PR and between 9da6f48 and 5765484.

📒 Files selected for processing (5)

• README.md
• demo/notebooks/00_seed_data.ipynb
• demo/notebooks/01_llama_index_property_graph.ipynb
• demo/notebooks/02_langchain_graph_chain.ipynb
• demo/notebooks/03_langgraph_agent.ipynb