docs: PRD rev1 re-review — repoint PRD heading anchors to GOV.4, complete archive line cites

Addresses CPS-PRD-REV1-REREVIEW findings on PR #1491 head 13968e9a:

F1 (blocker; the CI test failure): docs/PRD.md is now the permanent shim, so
heading-fragment links into the former PRD body no longer resolve —
fleet-documentation.spec.ts failed on docs/fleet/README.md's FCM anchor. The
Part II workstream contracts live in
docs/PRDs/2026-08-31_PRD_rev1/GOV.4-workstream-contracts.md; all five anchored
links in the tree are repointed there (fleet/README.md, TASKS.md,
release-integrity/TASKS.md, ADMIN-GUIDE mos-connector-lease-operations.md,
DEVELOPER-GUIDE mos-runtime-portability-m1.md). Each anchor verified against
the GOV.4 headings with the spec's slug rule. Bundle content unchanged.

F2 (minor): the rev0 archive README's ./ROADMAP.md row now cites all three
source lines (18, 177, 249).

docs/TASKS.md

@@ -59,7 +59,7 @@ Active workstream is **W1 — Federation v1**. Workers should:
 
 ## Fleet configuration management (#758) — M0–M5 implementation DAG
 
-> **PRD:** [Fleet declarative configuration management](./PRD.md#fleet-declarative-configuration-management-workstream-fcm-758) · **M0 acceptance:** [docs IA checklist](./fleet/FLEET-CONFIG-DOCS-IA-CHECKLIST.md) · **baseline dispositions:** [legacy example/profile inventory](./fleet/LEGACY-EXAMPLE-PROFILE-DISPOSITION-INVENTORY.md)
+> **PRD:** [Fleet declarative configuration management](./PRDs/2026-08-31_PRD_rev1/GOV.4-workstream-contracts.md#fleet-declarative-configuration-management-workstream-fcm-758) · **M0 acceptance:** [docs IA checklist](./fleet/FLEET-CONFIG-DOCS-IA-CHECKLIST.md) · **baseline dispositions:** [legacy example/profile inventory](./fleet/LEGACY-EXAMPLE-PROFILE-DISPOSITION-INVENTORY.md)
 >
 > Every row below is one independently reviewable card and **one PR**. `depends_on` is a
 > hard DAG edge; no card may silently absorb another card's scope. All source cards require