Hand the lab design off to mesh-lab

Playbook 04: the design names its owner and flips to in-progress. code
moves from hal to mesh-lab, and decisions gains 0029 and 0030 — the design
now rests on three records rather than one.

repos.md marks mesh-lab as the one target repository that exists. The
other six remain the target, not the present, and saying so is the point:
a map that lists repositories which do not exist is a map that will be
believed.

00-META/repos.md

@@ -21,7 +21,9 @@ and a forge address is an operational detail (see [`README`](../README.md)).
 ## What the mesh becomes
 
 [ADR 0030](../02-DECISIONS/0030-the-repository-structure.md) records the repositories the
-monorepo decomposes into. **None exist yet** — they are the target, not the present.
+monorepo decomposes into. **Only `mesh-lab` exists so far** — it is built first
+([ADR 0029](../02-DECISIONS/0029-the-labs-first-scenario-has-no-pipeline.md)); the rest are the
+target, not the present.
 
 | Repository | Tier | Holds |
 |---|---|---|
@@ -30,7 +32,7 @@ monorepo decomposes into. **None exist yet** — they are the target, not the pr
 | `mesh-control` | 2 | the control plane and its contexts |
 | `mesh-surfaces` | 3 | tools, web, cli |
 | `mesh-sdk` | — | contracts shared across tiers |
-| `mesh-lab` | — | the lab — built first, per [ADR 0029](../02-DECISIONS/0029-the-labs-first-scenario-has-no-pipeline.md) |
+| `mesh-lab` | — | **exists.** The lab — scenario lifecycle, networking, placement. Ships to nobody; runs on a workstation. |
 
 Tier 4's shape is open, and deliberately so: see ADR 0030 and
 [research 005](../01-RESEARCH/005-domain-grouping/00-overview.md).