Fix subpath deployment: set baseurl for /rmdb.github.io/ path

Pages is preview-served at https://daslab.stanford.edu/rmdb.github.io/
(a subpath under the DasLab org-level CNAME) until Phase 6 DNS cutover.
Root-relative paths were resolving against daslab.stanford.edu/ —
the browser was loading daslab.github.io's style.css and 404ing the
images, hence broken thumbnails + teal styling.

- _config.yml: baseurl = /rmdb.github.io
- _config_local.yml: override for `jekyll serve` local preview
- manifest.json: url + thumbnail through `relative_url` filter
- browse/index.html: inject MANIFEST_URL via inline script
- search.js: fetch window.MANIFEST_URL

CLAUDE.md (in rmdb_2026/) notes the two-line revert needed at DNS
cutover (restore CNAME + clear baseurl).

Move RDATs from git-LFS to GitHub Release assets (data-v1)

GitHub Pages does not transparently serve LFS-tracked files — Pages
returns the LFS pointer text instead of the actual file. Confirmed
by hitting the deployed /data/<ID>.rdat URL.

Switching to GitHub Release assets:
- 2 GB per-file limit (handles our biggest entries, ~290 MB).
- Unlimited storage, no bandwidth metering.
- Permanent CDN URLs.

Changes:
- _entries/*.md rdat: -> https://github.com/.../releases/download/data-v1/<ID>.rdat
- data/ now holds only a README; the 3 LFS-tracked .rdat files are removed.
- .gitattributes no longer LFS-tracks *.rdat (old LFS pointers remain
  in git history — small, harmless, free to leave).
- CONTRIBUTING.md updated: contributors now `gh release upload data-v1 <ID>.rdat`.
- README.md updated.

This unblocks Phase 3 bulk-import for all ~1032 entries.

Move RDATs from git-LFS to GitHub Release assets (data-v1)

GitHub Pages does not transparently serve LFS-tracked files — Pages
returns the LFS pointer text instead of the actual file. Confirmed
by hitting the deployed /data/<ID>.rdat URL.

Switching to GitHub Release assets:
- 2 GB per-file limit (handles our biggest entries, ~290 MB).
- Unlimited storage, no bandwidth metering.
- Permanent CDN URLs.

Changes:
- _entries/*.md rdat: -> https://github.com/.../releases/download/data-v1/<ID>.rdat
- data/ now holds only a README; the 3 LFS-tracked .rdat files are removed.
- .gitattributes no longer LFS-tracks *.rdat (old LFS pointers remain
  in git history — small, harmless, free to leave).
- CONTRIBUTING.md updated: contributors now `gh release upload data-v1 <ID>.rdat`.
- README.md updated.

This unblocks Phase 3 bulk-import for all ~1032 entries.

Move RDATs from git-LFS to GitHub Release assets (data-v1)

GitHub Pages does not transparently serve LFS-tracked files — Pages
returns the LFS pointer text instead of the actual file. Confirmed
by hitting the deployed /data/<ID>.rdat URL.

Switching to GitHub Release assets:
- 2 GB per-file limit (handles our biggest entries, ~290 MB).
- Unlimited storage, no bandwidth metering.
- Permanent CDN URLs.

Changes:
- _entries/*.md rdat: -> https://github.com/.../releases/download/data-v1/<ID>.rdat
- data/ now holds only a README; the 3 LFS-tracked .rdat files are removed.
- .gitattributes no longer LFS-tracks *.rdat (old LFS pointers remain
  in git history — small, harmless, free to leave).
- CONTRIBUTING.md updated: contributors now `gh release upload data-v1 <ID>.rdat`.
- README.md updated.

This unblocks Phase 3 bulk-import for all ~1032 entries.

Move RDATs from git-LFS to GitHub Release assets (data-v1)

GitHub Pages does not transparently serve LFS-tracked files — Pages
returns the LFS pointer text instead of the actual file. Confirmed
by hitting the deployed /data/<ID>.rdat URL.

Switching to GitHub Release assets:
- 2 GB per-file limit (handles our biggest entries, ~290 MB).
- Unlimited storage, no bandwidth metering.
- Permanent CDN URLs.

Changes:
- _entries/*.md rdat: -> https://github.com/.../releases/download/data-v1/<ID>.rdat
- data/ now holds only a README; the 3 LFS-tracked .rdat files are removed.
- .gitattributes no longer LFS-tracks *.rdat (old LFS pointers remain
  in git history — small, harmless, free to leave).
- CONTRIBUTING.md updated: contributors now `gh release upload data-v1 <ID>.rdat`.
- README.md updated.

This unblocks Phase 3 bulk-import for all ~1032 entries.

Move RDATs from git-LFS to GitHub Release assets (data-v1)

GitHub Pages does not transparently serve LFS-tracked files — Pages
returns the LFS pointer text instead of the actual file. Confirmed
by hitting the deployed /data/<ID>.rdat URL.

Switching to GitHub Release assets:
- 2 GB per-file limit (handles our biggest entries, ~290 MB).
- Unlimited storage, no bandwidth metering.
- Permanent CDN URLs.

Changes:
- _entries/*.md rdat: -> https://github.com/.../releases/download/data-v1/<ID>.rdat
- data/ now holds only a README; the 3 LFS-tracked .rdat files are removed.
- .gitattributes no longer LFS-tracks *.rdat (old LFS pointers remain
  in git history — small, harmless, free to leave).
- CONTRIBUTING.md updated: contributors now `gh release upload data-v1 <ID>.rdat`.
- README.md updated.

This unblocks Phase 3 bulk-import for all ~1032 entries.