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/PRDs/2026-08-26_PRD_rev0/README.md

@@ -19,7 +19,7 @@ with this table; every target still exists in the tree.
 | Link text in `PRD.md` (lines)                                   | Resolves to                                                                                                                |
 | --------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------- |
 | `./archive/PRD-v0.1.md` (17)                                    | [../../archive/PRD-v0.1.md](../../archive/PRD-v0.1.md)                                                                     |
-| `./ROADMAP.md` (18)                                             | [../../ROADMAP.md](../../ROADMAP.md)                                                                                       |
+| `./ROADMAP.md` (18, 177, 249)                                   | [../../ROADMAP.md](../../ROADMAP.md)                                                                                       |
 | `./requirements/native-kanban-sot.md` (98)                      | [../../requirements/native-kanban-sot.md](../../requirements/native-kanban-sot.md)                                         |
 | `./fleet/NORTH_STAR.md` (181)                                   | [../../fleet/NORTH_STAR.md](../../fleet/NORTH_STAR.md)                                                                     |
 | `./fleet/FLEET-CONFIG-DOCS-IA-CHECKLIST.md` (444)               | [../../fleet/FLEET-CONFIG-DOCS-IA-CHECKLIST.md](../../fleet/FLEET-CONFIG-DOCS-IA-CHECKLIST.md)                             |