chore(governance): stop declaring repository identity in settings.yml (#72)

`probot/settings` applies this file on **every push to the default
branch**, so the four identity
keys it declared are instructions, not documentation. The estate has
already paid for exactly this:
`.github/settings.yml` once read `name: "{{REPO}}"`, GitHub collapsed
the illegal braces to dashes,
the repository renamed itself to `-REPO-` on every push, its old URL
404'd, and it was read as a
deleted repository.

This repo still declared `name`, `description`, `homepage` and
`private`.

The repair is convergence on the source of truth, not new content:

- the header becomes the template's own header, which documents the
incident and the rule
  ("THIS FILE MUST NEVER DECLARE REPOSITORY IDENTITY");
- the four identity keys are removed; **everything else is unchanged** —
same repository settings,
  same 18 labels;
- repository identity and visibility stay set out of band, once, by the
owner.

Verified with the estate's own gate, `scripts/check-no-placeholders.sh`,
whose settings.yml guard
runs in template repos too (that exemption is how the original incident
went unseen). On this
branch the guard reports clean.

Author: hyperpolymath

.github/settings.yml

@@ -7,15 +7,45 @@
 # applied by the probot/settings app when changes are pushed to the default
 # branch. Install the app at: https://github.com/apps/settings
 #
-# Template file — replace systemet and systemet is a stratified type theory. The name is system + ET, where ET stands for Equality Theory — because the one primitive relation the whole system keeps at the bottom is equality, and everything else is layered above it as discipline rather than added as new relations. with actual values.
+# ─── THIS FILE MUST NEVER DECLARE REPOSITORY IDENTITY ─────────────────────────
+#
+# It carries NO `name`, `description`, `homepage` or `private` key, and it must
+# never gain one. The reason is a real incident, not a hypothetical:
+#
+#   This file previously read `name: "{{REPO}}"`. probot/settings applies it on
+#   every push to the default branch, so it submitted the literal string
+#   `{{REPO}}` as the repository name. GitHub sanitises an invalid name by
+#   collapsing each run of illegal characters to a dash — `{{REPO}}` became
+#   `-REPO-`. The template renamed itself on every push, its old URL 404'd, and
+#   it was mistaken for a deleted repository. `description` was likewise left
+#   reading the literal `{{DESCRIPTION}}` on the live repo.
+#
+# Two properties make identity keys unsafe here specifically:
+#
+#   1. This is a TEMPLATE. `just repo-init` fills placeholders in repos minted by the
+#      scaffolder — but GitHub's "Use this template" button copies the default
+#      branch verbatim and never runs `just repo-init`. Any placeholder left in a
+#      probot-managed file therefore reaches children unrendered.
+#   2. Identity is not shareable. The template must be public while children
+#      default private; a child cannot inherit either `name` or `private` from
+#      its parent without being wrong.
+#
+# Repository identity and visibility are therefore set OUT OF BAND: once per
+# repo, at creation time, by the operator (the Configure stage of ADR-0003).
+# `just repo-init` deliberately runs NO `gh` commands — it prints the exact
+# `gh repo edit` commands as next steps instead. Fail-closed default: repos
+# stay private unless the owner flips visibility deliberately; the template's
+# own name and visibility are set deliberately by the owner.
+#
+# Everything below is safe to inherit: it is true of every RSR repo regardless
+# of that repo's name, purpose or visibility.
+#
+# Enforced by `scripts/check-no-placeholders.sh`, which fails if this file
+# contains a `{{` token or declares any of the four identity keys.
 
 # ─── Repository Settings ───────────────────────────────────────────────────────
 
 repository:
-  name: "systemet"
-  description: "systemet is a stratified type theory. The name is system + ET, where ET stands for Equality Theory — because the one primitive relation the whole system keeps at the bottom is equality, and everything else is layered above it as discipline rather than added as new relations."
-  homepage: "https://github.com/hyperpolymath/systemet"
-  private: false
   has_issues: true
   has_projects: true
   has_wiki: false