chore: close spc-26 and record the ruling that adoption stays nameless

.abcd/development/intents/planned/itd-121-type-the-id-get-your-next-move-abcd-id-dispatches-on-a-recor.md → .abcd/development/intents/shipped/itd-121-type-the-id-get-your-next-move-abcd-id-dispatches-on-a-recor.md

@@ -84,4 +84,5 @@ is a future consideration, deliberately not an AC._
 
 ## Audit Notes
 
-_Empty. Populated by intent-fidelity-reviewer when intent moves to shipped/._
+<!-- abcd-review: OWED receipt=rcp-e85e544ece36 -->
+Fidelity review OWED (receipt rcp-e85e544ece36).

.abcd/work/issues/open/iss-2609110944498549-ahoy-install-must-not-write-abcd-by-name-into-a-target-repos.md

@@ -0,0 +1,77 @@
+---
+schema_version: 1
+id: "iss-2609110944498549"
+slug: "ahoy-install-must-not-write-abcd-by-name-into-a-target-repos"
+severity: "major"
+category: "ux"
+source: "user-observation"
+found_during: "v0.8.0 release review, maintainer ruling"
+origin: researcher-authored
+production_mode: hand-written
+found_at: "internal/core/ahoy/defaults/claude-md-marker-block.md"
+---
+
+**Maintainer ruling, 2026-09-11: `ahoy install` must not write abcd by name into
+a repository it adopts.** This record exists to carry that decision to the change
+that implements it.
+
+## What happens today
+
+`ahoy install` defaults `--docs-target` to `both`
+(`internal/core/ahoy/detect.go:28`), and `stepMarker`
+(`internal/core/ahoy/apply.go:866-900`) plants
+`internal/core/ahoy/defaults/claude-md-marker-block.md` into the target
+repository's committed `CLAUDE.md` **and** `AGENTS.md`. That block opens
+"Managed by abcd (Agent-Based Configuration for Development)" and carries a full
+"## abcd rule loader" section.
+
+So a default adoption commits abcd's name and its internals into somebody else's
+repository, and does so in files that repository's contributors read first.
+
+## Why it is wrong rather than merely surprising
+
+`prepare-this-repo` promises the opposite in its own acceptance criteria: "Given
+the adoption completes, then nothing from `private-names.txt` and no
+abcd-internal content appears in any committed artefact", reinforced by a
+Boundaries claim that the output is nameless and never mentions abcd.
+
+The v0.8.0 release gate caught the contradiction and the prose was corrected to
+describe what the code does
+(`.abcd/development/brief/04-surfaces/15-prepare-this-repo.md`). That was the
+right move for the record at the time and is now the wrong end to have fixed:
+the ruling is that the PROMISE was correct and the BEHAVIOUR should change.
+Implementing this therefore reverses that prose correction, deliberately.
+
+It is the same stance as
+[`the-users-directory-is-theirs`](../../development/principles/the-users-directory-is-theirs.md)
+and adr-2609091248200336, one level in: a tool does not create directories in
+space the user did not hand it, and it does not write its own name into files
+the user will commit under their project's history either.
+
+## What the change has to settle
+
+- **The marker still has to be findable.** Detection promotes a folder to
+  managed-repo on a marker block (`internal/core/ahoy/detect.go:139`,
+  `strong := registered || markerFired`), so whatever replaces the named block
+  must still be recognisable to `classify` and must not silently downgrade every
+  adopted repo to unmanaged.
+- **The rule loader has to keep working.** The block is not decoration; it is how
+  a session learns the loader exists. If the committed half goes nameless, the
+  loader's documentation has to live somewhere the adopting project chose.
+- **The default is the question, not just the text.** `--docs-target both` is
+  what makes this the out-of-the-box behaviour. Options include defaulting to
+  `skip`, keeping the block but stripping the name and the internals, or moving
+  the whole thing under `.abcd/` where the adopter already accepted a namespace.
+- **Registry-only adoption already exists** as the other strong signal, so a
+  nameless install is not a new mechanism, only a different default.
+
+## Acceptance
+
+- **Given** a repository adopted with default options, **when** the install
+  completes, **then** no committed file in that repository contains the string
+  "abcd" as a result of the install.
+- **Given** that same repository, **when** `ahoy` classifies it afterwards,
+  **then** it still reports managed-repo.
+- **Given** the `prepare-this-repo` acceptance criterion about nameless output,
+  **when** the change lands, **then** the criterion is true of the code and the
+  v0.8.0 prose correction is reversed in the same diff.