Add long version of MemOS paper

[Ki-Seki]

Include the long version of the MemOS paper in the documentation and update the citation details to reflect the new arXiv reference. Additionally, add a release note for the paper's publication date.

[Copilot]

Pull Request Overview

This PR updates the project documentation to include the long version of the MemOS paper, updates citation details to point at the new arXiv reference, and adds a release note for the paper’s publication date.

• Updated the arXiv badge link in the header to the long-paper reference.
• Replaced the BibTeX entry with a new @misc record corresponding to arXiv:2507.03724.
• Added a July 4, 2025 release note for the long-version paper.

Comments suppressed due to low confidence (4)

README.md:202

• [nitpick] Since this is the long version of the paper, consider using a distinct citation key (e.g., li2025memosLong) to avoid confusion with the short-paper entry.

@misc{li2025memos,

README.md:203

• Please confirm that the title field exactly matches the official long-version paper title on arXiv, including capitalization and wording.

    title={MemOS: A Memory OS for AI System},

README.md:208

• Add a trailing comma after the primaryClass field for consistency and to ensure valid BibTeX syntax.

    primaryClass={cs.CL}

README.md:226

• [nitpick] For consistency with the new entry’s wording (*MemOS Paper Released*), consider changing "Short Paper Uploaded" to "Short Paper Released".

- **2025-05-28** – 🎉 *Short Paper Uploaded*: [MemOS: An Operating System for Memory-Augmented Generation (MAG) in Large Language Models](https://arxiv.org/abs/2505.22101) was published on arXiv.