Tidy the legacy content out of .github

[davison]

Goal

Leave .github holding only what other repos still use: the two reusable release workflows (called by tradedesk and tradedesk-dukascopy), the calculate_version action, and the org profile (profile/README.md, banner). Remove the dead blog scaffolding: _config.yml, mkdocs.yml, index.html (a redirect to /blog/), docs/index.md (points at a radiusred/blog repo that no longer exists), requirements.txt. Move doc/radius-red.drawio to radiusred/ha-sinkhole next to the SVGs it generates (it only contains ha-sinkhole diagrams; confirmed by the operator 2026-09-02), with a follow-up PR there. Rewrite CONTRIBUTING.md to describe the org as it is now: it lists only the three tradedesk repos and cross-repo documentation that is gone. Do not touch the workflows or the action.

Requirements

M1-R2

Plan

Requirement covered: M1-R2. Implementer: radiusred-cody.

Intended changes, one commit each, on the task branch:

1. chore: remove the dead blog scaffolding (#35) — delete _config.yml, mkdocs.yml, index.html, docs/index.md and requirements.txt. Nothing is served from them: the repo's Pages setting is build_type: workflow and no Pages workflow exists here, and a code search across the org finds no consumer of radiusred.github.io/.github/ (the two hits are infrastructure's codecrew.works DNS record and the ops web-presence plan, both about the org-apex radiusred.github.io, not this repo's site).
2. docs: rewrite CONTRIBUTING.md for the org as it is (#35) — say what .github holds (the two reusable release workflows and who calls them — tradedesk and tradedesk-dukascopy, found by code search — the calculate_version action, the org profile), how changes to it are made (PR against main, conventional commits, rebase-only linear history, a change to a reusable workflow is a change to every caller), and point contributors at each repository's own CONTRIBUTING.md and the org profile instead of enumerating three trading repos. No cross-repo documentation lives here any more, so the file stops claiming it does.
3. doc/radius-red.drawio — blocked on ask-the-human point 1 below. Whichever answer comes back, the .github side is a one-file chore: commit on this branch; the ha-sinkhole side (if any) is a follow-up PR there under the same App identity, cross-linked to this task and the .github PR.

Left exactly as they are: .github/workflows/reusable-release.yml, .github/workflows/reusable-finalize-release.yml, .github/actions/calculate_version/*, profile/*, .codecrew.yml, .gitignore.

Tests: none ride with this PR because no code changes — the workflows and the action are untouched by instruction, and everything removed or rewritten is prose or dead site config. Verification is git ls-files on the branch showing only the kept set.

Observations for the operator, not gates: (a) the org require-lint ruleset makes "Lint commit messages" a required check on this repo's main, but this repo has no commitlint workflow, so the check can never report on a .github PR; adding one is a workflow change and out of this task's scope. (b) Pages stays enabled on the repo with nothing to build; disabling it is a repo setting, not a file, so it is out of scope here too.

Ask-the-human points

1. What does "move doc/radius-red.drawio to ha-sinkhole" mean now that ha-sinkhole already has the source? ha-sinkhole already holds .files/ha-sinkhole-architecture.drawio next to the three *.drawio.svg files, with the same three diagram ids (overview, dns-resolver, logo) and an edit history from 2025-11-13 to 2026-01-09. The shipped SVGs were rendered from that file: they say dns-resolver throughout and contain none of the .github copy's additions. The .github copy (committed 2026-02-16, saved with a newer draw.io) is a divergent draft: it still uses the pre-rename dns-node name on the second page and in two swimlanes, and adds an "upstream resolvers" cloud, two :12345 port labels and a provided/required-interface shape on the dns-node page that never reached the SVGs. So the requirement's "the draw.io source for ha-sinkhole's diagrams lives in ha-sinkhole" is already true, and the question is what to do with this fork. The options I see:
   • (a) copy it into ha-sinkhole as a second file (e.g. .files/radius-red.drawio) — literal to the task, but leaves two divergent sources side by side, the newer-saved one with the stale naming;
   • (b) delete it from .github and open no ha-sinkhole PR — the annotations added in February are lost;
   • (c) port the February additions (upstream-resolvers cloud, port labels, interface) into .files/ha-sinkhole-architecture.drawio and regenerate the SVGs — a content change to ha-sinkhole's architecture docs, which is a decision about that project, not a tidy-up.
     Which one? I will proceed with changes 1 and 2 and open the .github PR as a draft; the drawio commit and any ha-sinkhole PR wait for the answer.

[radiusred-cody]

Started by @radiusred-cody[bot].

[radiusred-cody]

Gate raised: ha-sinkhole already holds the draw.io source for its diagrams (.files/ha-sinkhole-architecture.drawio, which is what the shipped SVGs were rendered from). doc/radius-red.drawio is a divergent draft of it: pre-rename dns-node naming plus an upstream-resolvers cloud, :12345 port labels and an interface shape that never reached the SVGs. What should happen to it: (a) copy it into ha-sinkhole as a second file alongside the canonical one, (b) delete it from .github with no ha-sinkhole PR, or (c) port its February additions into the canonical source and regenerate the SVGs? Detail in the Ask-the-human section of the issue body. Changes 1 and 2 are on the draft PR already; the drawio commit and any ha-sinkhole PR wait for this answer.

Resolve by replying with a comment starting **Gate resolved:** — the decision, and the trade-off if one was weighed — then removing the cc:needs-decision label. The resolution is gathered into the milestone record; task finish refuses while the label is present or the gate lacks a resolution comment.

[radiusred-cody]

Note: gh codecrew task start could not assign @radiusred-cody[bot] to this issue (GitHub returned 403 on the assignment; App bot users cannot be issue assignees). The task is started as the App and the linked branch task/35-tidy-the-legacy-content-out-of-github was created; the draft PR is the record of who is doing the work.

[davison]

Decision (operator, 2026-09-03): the .github copy doc/radius-red.drawio is the more up-to-date of the two. Move it to ha-sinkhole and overwrite .files/ha-sinkhole-architecture.drawio with it, keeping that filename. The gate is answered; proceed with the move and the ha-sinkhole follow-up PR.

[radiusred-cody]

Gate acted on. doc/radius-red.drawio is removed from this repository in #36 (commit 2d459d6) and lands byte-for-byte in ha-sinkhole as .files/ha-sinkhole-architecture.drawio via radiusred/ha-sinkhole#117 (commit 7badae7), overwriting the previous copy under that filename as decided above. The SVGs there are not regenerated; the ha-sinkhole PR records that they are now behind the source as an observation. #36 is out of draft and ready for review.