Delete obsolete migrate-substrate-11360 script

Context

ADR 0004 moved resources/content/ to the Universal Ordinal-100 Content Architecture and explicitly anchors recovery on clean deletion plus sync_all regeneration. During PR #11403 follow-up review, ai/scripts/migrate-substrate-11360.mjs stood out as leftover one-shot substrate code from the pre-ADR #11360 cleanup path.

This ticket exists because the script now points in the wrong architectural direction: it preserves a migration affordance after the architecture has chosen a clean cut.

The Problem

ai/scripts/migrate-substrate-11360.mjs is a one-shot repair script introduced for #11360 / PR #11362. It remains tracked after that migration completed and after ADR 0004 established the new source-of-truth model.

Current evidence:

• ai/scripts/migrate-substrate-11360.mjs:2 identifies itself as a one-shot script for Epic #11187 Phase 6 sub-issue #11360.
• ai/scripts/migrate-substrate-11360.mjs:29-31 still advertises manual --dry-run / --apply execution.
• ai/scripts/migrate-substrate-11360.mjs:56 defines local chunkPath() for the retired pre-ADR ID-range model.
• ai/scripts/migrate-substrate-11360.mjs:171, :208, and :232-233 still generate retired resources/content/issues/<NNN>xx/ and resources/content/pulls/pr-<NNN>xx/ paths.
• rg migrate-substrate-11360 found no live consumer outside the script itself.
• Git history preserves the audit trail: 559c73d43 introduced the script for #11360 / #11362, and 79ac1f8c9 only adjusted its comment while deleting retired path helpers for #11390 / #11403.

The Architectural Reality

ADR 0004 is the source of authority:

• learn/agentos/decisions/0004-github-content-architecture.md:51-53 states resources/content/ and .sync-metadata.json are regeneratable; sync_all is the recovery mechanism.
• learn/agentos/decisions/0004-github-content-architecture.md:68-84 defines the target shape as universal chunk-N/ directories with no <NNN>xx/, no GitHub-ID-stream math, and one primitive.
• learn/agentos/decisions/0004-github-content-architecture.md:284-294 rejects deprecation or coexistence windows for retired primitives and prescribes deletion when migration lands.

Keeping the old script creates a misleading executable artifact for future agents and conflicts with the clean-cut mental model. Git history is sufficient audit trail; tracked executable substrate should reflect the current architecture.

The Fix

Delete ai/scripts/migrate-substrate-11360.mjs.

Do not replace it with a new migration script, shim, wrapper, or compatibility alias. If local resources/content/ state needs repair, the operator or agent should use the ADR 0004 recovery path: clean substrate deletion where needed, then run sync_all from dev.

Coordinate with #11406 if its retired-primitive grep enforcement lands first or in parallel, so the deleted script does not require a special allowlist.

Acceptance Criteria

• ai/scripts/migrate-substrate-11360.mjs is deleted.
• No new migration script or compatibility shim is added for #11360.
• rg "migrate-substrate-11360|function chunkPath|pr-\\$\\{chunkPath|issues/\\$\\{chunkPath" ai buildScripts test package.json finds no live-code reference requiring the retired ID-range model.
• The PR body cites ADR 0004 and explains that Git history preserves the #11360 audit trail.
• If #11406 grep enforcement is already merged, its check passes without an allowlist entry for this deleted script.

Out of Scope

• Rewriting contentPath.mjs or syncer chunk semantics.
• Mutating resources/content/ data files.
• Running sync_all from a feature branch.
• Deleting or rewriting historical GitHub issue, PR, or ADR content that references the old model.
• Updating unrelated release JSDoc comments unless the close-out lane explicitly owns that scope.

Related

• Parent Epic: #11372
• Predecessor cleanup ticket: #11360
• PR #11362 introduced the one-shot script for the old cleanup path.
• PR #11403 deleted the retired shared path helpers and exposed this script as the remaining live executable artifact.
• #11406 tracks CI grep-fail enforcement for retired primitive imports.
• ADR 0004: learn/agentos/decisions/0004-github-content-architecture.md

Origin Session ID: 56d01d8b-ce3f-4194-9441-e4941ae07be8

Handoff Retrieval Hint: "ADR 0004 migrate-substrate-11360 clean cut sync_all retired chunkPath"