docs: document development workflows, update other documents

[dhl123]

Summary

This PR created a CONTRIBUTING.md for developer, and updated README.md, CLAUDE.md, CHANGELOG.md based on recent changes.

Closes: #48

[araujof]

A few findings:

• HR setup breaks tool calls. CONTRIBUTING.md:168 sets MCP_URL to the agent’s tool-definition endpoint, but examples/hr-agent/agent.py:371 POSTs tool calls to that same variable. Override it with http://localhost:9100/mcp when starting the agent or separate the variables.

• Security release notes are deleted. CHANGELOG.md:18 removes main’s NLTK/dependency-remediation security entry and dependency-upgrade entry. These unrelated changes should be restored.

• Test coverage is overstated. README.md:115 claims every stage has a unit/integration pair, but get_current_agent and open_explorer have no unit modules. Adjust the wording or add the tests.

• Linked issue acceptance criteria are unmet. Issue #48 explicitly requests DEVELOPMENT.md; the PR adds no such file. Its summary also claims Hugo documentation updates, but only four root Markdown files changed.

[dhl123]

A few findings:

• HR setup breaks tool calls. CONTRIBUTING.md:168 sets MCP_URL to the agent’s tool-definition endpoint, but examples/hr-agent/agent.py:371 POSTs tool calls to that same variable. Override it with http://localhost:9100/mcp when starting the agent or separate the variables.
• Security release notes are deleted. CHANGELOG.md:18 removes main’s NLTK/dependency-remediation security entry and dependency-upgrade entry. These unrelated changes should be restored.
• Test coverage is overstated. README.md:115 claims every stage has a unit/integration pair, but get_current_agent and open_explorer have no unit modules. Adjust the wording or add the tests.
• Linked issue acceptance criteria are unmet. Issue docs: document development workflows #48 explicitly requests DEVELOPMENT.md; the PR adds no such file. Its summary also claims Hugo documentation updates, but only four root Markdown files changed.

Q1, Q2, and Q3 are fixed.

For Q4, the development workflow has been included in CONTRIBUTING.md. The PR description changed.

[araujof]

LGTM