docs: link the technical report on arxiv and hugging face

[LivXue]

Summary

The technical report is now on arXiv as 2609.33439, with a paper page
on Hugging Face. This points the READMEs at those two pages instead of
the tech-report-v1 Release PDF, and switches the citation to the
arXiv entry.

• Both READMEs: the report link that leads the navigation line under
  the badges becomes two links, arXiv and the Hugging Face paper page.
  The Citation sentence now links the arXiv abstract page.
• Badge row, both READMEs: an arXiv badge (2609.33439) joins it beside
  the X badge, and the HuggingFace badge is relabelled Paper and points
  at the paper page instead of the organisation page.
• The navigation line under the badges drops its two report links, now
  that the badges carry them, and keeps Website, Documentation and the
  language switch.
• BibTeX, in all three copies (both READMEs and
  docs/technical-report/README.md, still byte-identical):
  @techreport becomes arXiv's @misc form with eprint,
  archivePrefix and primaryClass. institution and month are
  dropped, as arXiv's export carries neither.
• Two deliberate departures from arXiv's generated export. The key
  stays evermind2026raven, so existing citations keep resolving.
  Author and title keep their double braces: arXiv parses "EverMind
  AI" as a person (its citation_author reads "AI, EverMind", which
  is where its generated key ai2026ravenharnessharnessescomposable
  comes from), so the verbatim export cites as "AI [2026]" under
  natbib author-year, and as "E. AI" with a lowercased title under
  abbrv.
• docs/technical-report/README.md keeps its Release download and
  adds the two links. The Release PDF and arXiv v1 are the same
  document: 82 pages each, and a word-level diff of their text is
  empty apart from arXiv's margin stamp.

Not changed in git: the tech-report-v1 Release notes held a fourth
copy of the old @techreport entry. It is outside the repository; its
notes were updated to the same entry, and /releases/latest was
re-checked afterwards and is still the software release.

Type

• Fix
• Feature
• Docs
• CI / tooling
• Refactor
• Other

Verification

Run at the branch head, with the repository's Python 3.12 environment:

PYTHONPATH=. python scripts/check_large_files.py origin/main..HEAD
PYTHONPATH=. python scripts/check_source_language.py origin/main..HEAD
PYTHONPATH=. python scripts/check_commit_messages.py origin/main..HEAD
commitlint --from origin/main --to HEAD --config commitlint.config.cjs
pre-commit run --from-ref origin/main --to-ref HEAD
python -m pytest -q tests/test_living_docs.py \
  tests/test_cli_onboard_commands.py::test_readme_quickstart_matches_the_installer \
  tests/test_docker_runtime.py::test_container_exposes_no_engine_selector

The four gates exit 0; every pre-commit hook that applies passes and
modifies no file; pytest reports 4 passed: the living-docs scan and
the two tests that read the root READMEs.

• Links: https://arxiv.org/abs/2609.33439 and
  https://huggingface.co/papers/2609.33439 both return HTTP 200, and
  both pages carry the report's exact title.

• BibTeX: the entry compiles without warnings under bibtex with
  plain, abbrv and plainnat, and under biber with biblatex
  numeric, which prints arXiv: 2609.33439 [cs.AI].

• Rendering: GitHub's own render of all three files at the branch
  head; every new link carries the intended href, and each file
  renders one bibtex code block.

• The three BibTeX blocks share one sha256.

• Relevant tests pass locally

• Relevant lint / type checks pass locally

• User-facing docs or screenshots are updated when needed

Risk

Documentation only: three Markdown files, no code. The README
navigation line and Citation section change for readers. Existing
citations keep their key, and the Release and its download URL are
untouched, so old links still resolve. Roll back by reverting the
squash commit.

• Security impact considered
• Backward compatibility considered
• Rollback path is clear for risky changes

Related Issues

N/A

[gloryfromca]

No blockers; this can merge as far as I am concerned.

Reviewed the complete PR diff against its actual GitHub base, the surrounding report documentation and introduction history, and the current external destinations. The arXiv and Hugging Face pages resolve to the intended report; the title, identifier, author, and primary class match the citation. The three BibTeX copies remain aligned, the stable citation key is preserved, and the release PDF links remain available on the report landing page.

I also covered the repository rules, backward compatibility, test changes (none), and architecture/caller impact (none for this documentation-only change). git diff --check and the large-file, source-language, and commit-message gates passed. After uv sync --all-packages, the focused test command passed with 4 tests. The initial fresh-environment attempt could not collect because the workspace plugin raven_everos was not installed; syncing the declared workspace packages resolved that environment issue without changing the worktree. GitHub's documentation, lint, repository, installer, TUI, bridge, and contract checks visible at review time are passing; the sharded unit jobs are still running.