docs(licence): record GitHub single-display resolution (Addendum A8)

GitHub surfaces only one repo-level licence (licensee-detected from the
root LICENSE). Rule 1's per-file split (MPL-2.0 code / CC-BY-SA-4.0 prose)
cannot be shown at the repo level, so the estate resolves the single
displayed licence to MPL-2.0 — root LICENSE = MPL-2.0, both texts present
in LICENSES/, prose stays CC-BY-SA-4.0 by per-file header. Adds Addendum
A8 to LICENCE-POLICY.adoc and a [github_display] block to the machine-
readable mirror. Additive only; Rules 1-3 unchanged; no per-file licence
header is modified.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012MpYSh6Wy8YMBH2E3qVyT7

Author: claude

.machine_readable/licensing-policy.toml

@@ -22,6 +22,14 @@ meaning = "Creative Commons Attribution-ShareAlike 4.0 International"
 scope = "narrative documentation (*.adoc, *.md) in sole-owner repos"
 status = "owner ruling 2026-06-04 — docs are CC-BY-SA-4.0; code stays MPL-2.0"
 
+[github_display]                         # Addendum A8 (2026-07-01)
+resolved_to = "MPL-2.0"
+reason = "GitHub surfaces only one repo licence (licensee-detected from root LICENSE). Rule 1's per-file MPL/CC-BY split cannot be shown at repo level, so the single displayed licence is resolved to MPL-2.0."
+root_license = "MPL-2.0 text (drives GitHub's detected licence badge)"
+both_texts_present = ["LICENSES/MPL-2.0.txt", "LICENSES/CC-BY-SA-4.0.txt"]
+prose_licence = "CC-BY-SA-4.0 declared per-file (SPDX header) + LICENSES/CC-BY-SA-4.0.txt; NOT via a second root licence file"
+note = "display resolution, not relicensing; Rule 1 unchanged"
+
 [palimpsest_carveout]                    # Rule 2 — narrow, NOT the default
 spdx = "PMPL-1.0-or-later"
 applies = "EXACTLY three repos: palimpsest-license, palimpsest-plasma, consent-aware-http (the last prospectively)"

LICENCE-POLICY.adoc

@@ -244,6 +244,31 @@ audited and tightened. Genuine contradiction §C-C4 (zotero-voyant-export
 `ECHIDNA_ARCHITECTURE_UPDATE_3LANG.md`) is **not** on this list — it is
 a real defect tracked for an owner-directed single-file fix.
 
+=== A8 — GitHub single-licence display resolved to MPL-2.0 (2026-07-01)
+
+GitHub surfaces only *one* repository licence — the one its licensee
+detector reads from the root `LICENSE` file. Rule 1 splits per-file SPDX
+two ways (MPL-2.0 for code, CC-BY-SA-4.0 for prose), which GitHub cannot
+represent at the repo level. The estate therefore resolves the single
+GitHub-displayed licence to **MPL-2.0**: every repo's root `LICENSE`
+carries the MPL-2.0 text, so the GitHub sidebar shows `MPL-2.0`. Both
+canonical texts remain present in every repo — `LICENSES/MPL-2.0.txt`
+and `LICENSES/CC-BY-SA-4.0.txt` (REUSE-style) — and prose stays
+CC-BY-SA-4.0 by its per-file SPDX header. This is a *display resolution,
+not a relicensing*; Rule 1 is unchanged.
+
+Mechanical consequences (what every repo ships):
+
+* Root `LICENSE` = MPL-2.0 text (drives GitHub's detected licence).
+* `LICENSES/` carries *both* `MPL-2.0.txt` and `CC-BY-SA-4.0.txt`.
+* Prose files declare CC-BY-SA-4.0 via their own SPDX header plus the
+  `LICENSES/CC-BY-SA-4.0.txt` text — not via a second root licence file.
+
+A separate `LICENSE-docs` (CC-BY-SA-4.0) file, as a few repos ship, is an
+acceptable equivalent for surfacing the prose licence, but the `LICENSES/`
+REUSE directory is the canonical carrier and the root `LICENSE` stays
+MPL-2.0 so the single GitHub display resolves as above.
+
 == See Also
 
 * `PALIMPSEST.adoc` (this directory) — full narrative