Rebuild for the 2027 Annual Meeting (v7.0 Lite)

[zihaooo]

Summary

The class currently describes the 2027 Annual Meeting changes but still
ships the word-count-era layout and natbib + trb.bst. This PR rebuilds
the class so it actually implements the 2027 requirements and modernizes
the toolchain, matching the official 2026 sample paper.

What changed

Bibliography (the big one)

• Replaced natbib + trb.bst with biblatex configured for Chicago
  author–date, built into the class.
• Uses backend=bibtex, so no biber is required — latexmk,
  Overleaf, and tectonic all work out of the box.
• Deleted the now-unused trb.bst.

Layout (matches the 2026 sample)

• Page number centered in the footer; italic author running header.
• FIGURE N / TABLE N bold captions via the caption package.
• Author emails black; DOI/URL links blue.

Requirements implemented

• 20-page limit shown via an automatic page count on the title page.
• \abstractpart{...} helper for the required structured abstract.
• Chicago author–date references, sorted alphabetically.
• All authors on the title page; AI/LLM-use disclosure in Acknowledgments.

Modernization

• caption (was ccaption), added microtype, author macros rewritten
  with \NewDocumentCommand.

Docs

• README rewritten for the 2027 workflow, with pdfLaTeX/Overleaf as the
  primary build path.

Breaking changes

• \TRBauthor signature is now
  \TRBauthor[*]{Name}{Affiliation (multi-line, use \\)}{email}[ORCID].
  The separate optional [address] is gone — put address lines in the
  affiliation argument.
• Bibliography commands: use \addbibresource{...} + \printbibliography
  instead of \bibliographystyle{trb} + \bibliography{...}. In-text
  \citep/\citet still work (via natbib=true).

Build

latexmk -pdf trb_template.tex, Overleaf (pdfLaTeX), or tectonic trb_template.tex. The main .tex can be renamed freely.

Notes for reviewers

• References are alphabetical (Chicago author–date convention).
• "et al." is used for 3+ authors in text, matching the sample.
• Title size is left at the original \large different from the Word template.