Archived public repos carry a type; snapshots declare their backing content

[Ethan-Arrowood]

Doc side of the public-archive cleanup — HarperFast/ospo#115, part of #66. The dispositions for all 57 public archived repos are proposed here; this PR makes the policy and taxonomy say what we're now doing.

What changes

Type lives in the repo-type custom property, not a GitHub topic. The doc still described the topic projection, which effectively never ran — only two public repos ever carried a type topic. The property has been live on every public active repo since ospo#113. GitHub enforces the value list, only org admins can write it, and it reads org-wide in one call.

Scope widens from "active, public" to "public". An archived repo keeps its taxonomy type and its archive note, and is exempt from the rest of the requirements — it's read-only by definition. An archived repo's type is precisely what tells a reader what they're looking at, so dropping it on archival threw away the useful part.

Keep-public vs. move-internal becomes a judgment with a stated reason. The old text defaulted to public because "the cost is low." That's the part worth revisiting: a stale public repo is training surface, and old practices keep teaching humans and agents the wrong thing long after the code stops mattering. The new text asks for the reference value to be weighed against that per repo, with the evidence recorded. This also replaces the standing aside about the old Custom Functions repos, whose disposition is now decided.

Snapshots declare their backing content in the repo homepage field and link it in the archive note. Tooling reads homepage, so the link doesn't depend on README prose surviving. It also gives us a test for the type itself: no dated artifact, not a snapshot. None of the 10 public snapshot repos has homepage set today; that's being backfilled in the same pass.

Archive note links use the harper.fast forms (docs.harper.fast, harper.fast/discord) rather than the docs.harperdb.io / discord.com/invite/... URLs they resolve to. The notes added so far are split between the two.

The "adapt the wording" guidance is spelled out — superseded repos, repos that produced a published package, repos where no pinned version applies, and non-Markdown READMEs (sdk-java is AsciiDoc, where a Markdown alert renders as literal text).

Notes for review

• The deep links to docs.harperdb.io elsewhere in the taxonomy doc are left alone — the decision was scoped to the archive note. docs.harper.fast preserves paths, so normalizing the rest is a clean follow-up if wanted.
• "Automated checks (topic present…)" in the roadmap becomes "repo-type set".

[gemini-code-assist]

Code Review

This pull request updates the repository policy and taxonomy documentation to transition from using GitHub topics to the repo-type organization custom property for classifying public repositories. It also refines the guidelines for archiving repositories, including when to keep them public versus moving them internal, and introduces metadata requirements for snapshot repositories. The review feedback focuses on improving the clarity and professionalism of the documentation, suggesting more precise phrasing regarding the property settings for private repositories, the decision-making process for archiving, and the classification of archived repos.