docs(canon): define prj- project repository flavor

Publish project-repository-flavor_v0.1 with naming, GOAL.md (not durable
INTENT.md), authority boundary, lifecycle, residuals, and archive rules.
Close ADR-005 deferred naming and CUST-WP-0050 D1a; cross-link from the
repo classification standard.

workplans/CUST-WP-0050-repo-classification-registration-redesign.md

@@ -344,11 +344,12 @@ recorded exclusion list).
   classification; `topic`/`domain` stop being the spine (`topic` retires or
   becomes an optional cross-repo tag). This supersedes the earlier "keep topic as
   an independent coordination unit" proposal. Implemented by T04/T10.
-- **D1a (open, follows from D1): anchor for cross-repo workplans.** Per **ADR-005**,
-  a complex cross-repo effort gets its own **project repo** (`category: project`)
-  as the anchor, retired to archive on completion with results living in the
-  modified product repos. Open sub-point: the project-repo **naming convention**
-  (e.g. `proj-<slug>` vs a dedicated grouping) and the archival trigger details.
+- **D1a (RESOLVED 2026-08-09, follows from D1): anchor for cross-repo workplans.**
+  Per **ADR-005**, a complex cross-repo effort gets its own **project repo**
+  (`category: project`) as the anchor, retired to archive on completion with
+  results living in the modified product repos. Naming, files, lifecycle, and
+  archive procedure: `canon/standards/project-repository-flavor_v0.1.md`
+  (`prj-<slug>`, `GOAL.md` not durable-product `INTENT.md`).
 - **D2: classification ownership/approval.** Who approves each repo's
   `.repo-classification.yaml` — per-repo owner, or central custodian review?
 - **D3 (RESOLVED 2026-06-22): exclusion list.** Recorded at