docs(planning): promote portable-planning-convention bundle on ship

First exercise of the convention's own promotion step: move the bundle from
changes/active/ to changes/archive/, set status: shipped + pr: 55, and shift
its README Index line from Active to Archived.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lesnik512

planning/README.md

@@ -70,12 +70,11 @@ carry **no** frontmatter — living prose, dated by git.
 
 ### Active
 
-- **[portable-planning-convention](changes/active/2026-06-13.03-portable-planning-convention/design.md)**
-  (2026-06-13) — Adopt the portable two-axis convention: per-capability
-  `architecture/` truth files + `changes/` bundles, full history backfill,
-  byte-identical Conventions. *This change.*
+_None._
 
 ### Archived (shipped)
+
+- **[portable-planning-convention](changes/archive/2026-06-13.03-portable-planning-convention/design.md)** (#55, 2026-06-13) — Adopt the portable two-axis convention: per-capability `architecture/` truth files + `changes/` bundles, full history backfill, byte-identical Conventions.
 - **[circuit-breaker-and-timeout](changes/archive/2026-06-13.02-circuit-breaker-and-timeout/design.md)** (#51, 2026-06-13) — Shipped 0.10.0 — CircuitBreaker + AsyncTimeout
 - **[msgspec-nested-customtype-fix](changes/archive/2026-06-13.01-msgspec-nested-customtype-fix/design.md)** (#43, 2026-06-13) — Shipped 0.9.1 — nested-CustomType guard
 - **[delta-audit](changes/archive/2026-06-12.01-delta-audit/design.md)** (#43, 2026-06-12) — 0.9.0 delta audit; closed via 0.9.1

…3-portable-planning-convention/design.md …3-portable-planning-convention/design.mdplanning/changes/active/2026-06-13.03-portable-planning-convention/design.md renamed to planning/changes/archive/2026-06-13.03-portable-planning-convention/design.md planning/changes/active/2026-06-13.03-portable-planning-convention/design.md renamed to planning/changes/archive/2026-06-13.03-portable-planning-convention/design.md

@@ -1,11 +1,11 @@
 ---
-status: draft
+status: shipped
 date: 2026-06-13
 slug: portable-planning-convention
 supersedes: null
 superseded_by: null
-pr: null
-outcome: null
+pr: 55
+outcome: 'Shipped via PR #55 — two-axis convention adopted: architecture/ truth + planning/changes/ bundles; engineering.md split into 8 files; 40 pairs archived.'
 ---
 
 # Design: Adopt the portable two-axis planning convention

….03-portable-planning-convention/plan.md ….03-portable-planning-convention/plan.mdplanning/changes/active/2026-06-13.03-portable-planning-convention/plan.md renamed to planning/changes/archive/2026-06-13.03-portable-planning-convention/plan.md planning/changes/active/2026-06-13.03-portable-planning-convention/plan.md renamed to planning/changes/archive/2026-06-13.03-portable-planning-convention/plan.md

@@ -1,9 +1,9 @@
 ---
-status: draft
+status: shipped
 date: 2026-06-13
 slug: portable-planning-convention
 spec: portable-planning-convention
-pr: null
+pr: 55
 ---
 
 # portable-planning-convention — implementation plan