Add shields.io badges and MIT LICENSE file

[sebastientaggart]

Add a MIT LICENSE file and 7 shields.io badges to the README for project credibility and trust signals: CI status, license, release version, last commit, PRs welcome, Python tech stack, and git submodule install method. Update the license section at the bottom of the README to link to the new LICENSE file.

Issue #120

[sebastientaggart]

Review Summary

Verdict: APPROVE

Findings

• [NOTE] The SKILL.md heading change from ## Resolution to ### Resolution Notes is unrelated to the stated PR scope (badges and LICENSE); this is fine but worth noting as an incidental change.
• [NOTE] The LICENSE copyright year says 2025 — confirm this is intentional given the current date is 2026.

No correctness, security, or convention issues found. The LICENSE file is standard MIT, the badges are well-formed shields.io links pointing to correct targets, and the README license section now links to the new file.