feat: add Jupyter notebook with e2e operations examples

[Copilot]

Adds interactive Jupyter notebook demonstrating c8ctl operations end-to-end, targeting localhost:8080 with Node.js v22 LTS.

Implementation

Notebook (examples/e2e-operations.ipynb)

• 12 sections covering deployment, process instances, user tasks, messages, incidents, jobs, plugins
• Auto-detects Node.js version: native TS on v22+, falls back to compiled JS on v20+
• Smart path resolution handles different Jupyter kernel implementations
• Uses existing BPMN fixtures: simple.bpmn, min-usertask.bpmn, bb-process.bpmn

CI Validation (.github/workflows/e2e-notebook.yml)

• Validates each operation independently against Camunda 8.8
• Tests complete workflows: deploy → create → list → complete user tasks
• Runs on PR changes to examples/, src/, or workflow

Supporting Assets

• Setup documentation with tslab/IJavascript kernel installation
• Bash test script for local validation without Jupyter
• Main README updated with Learning Resources section

Example Usage

// Notebook cell - deploys, creates instance, completes user task
c8('deploy tests/fixtures/list-pis/min-usertask.bpmn');
const output = c8('create pi --bpmnProcessId=Process_0t60ay7', { silent: true });
const key = output.match(/Key: (\d+)/)?.[1];
c8(`complete ut ${key} --variables='{"approved":true}'`);

Notebook cells execute sequentially via Shift+Enter, demonstrating happy path operations with real Camunda interactions.

Original prompt

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This section details on the original issue you should resolve

<issue_title>create a Notebook with e2e operation examples</issue_title>
<issue_description>- assume localhost:8080 for the Camunda cluster

• Notebook should run Node.js v22 LTS
• e2e scope with happy path
• advanced functionality including user tasks and plugins
• take sample bpmns in the repo for this
• try all journeys in a gh action first to make sure they work when the Notebook is executed locally</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes create a Notebook with e2e operation examples #19

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