chore(deps): bump ZB.MOM.WW.LocalDb 0.1.3 -> 0.2.1, correct the MaxBatchSize rationale

Closes the pin skew against ScadaBridge (which already pins 0.2.1). Pure pin
bump — no code change was required:

- `RegisterReplicated(string)` still delegates to `baselineExistingRows: false`,
  so `LocalDbSetup.OnReady` is byte-identical in behaviour.
- Everything 0.2.x added is additive (`DeregisterReplicated`, `MaxBatchBytes`,
  the `baselineExistingRows` overload); none of it is called here.
- The wire protocol is unchanged (0.1.x peers still sync) and the on-disk
  bookkeeping schema v1 -> v2 upgrades in place on open, so no rig, volume or
  operator action is needed.

The one thing that DID need reconciling is documentation. 0.2.0 made batching
byte-budgeted: `MaxBatchBytes` (2 MB default, under the 4 MB gRPC cap) now
bounds the wire message, and `MaxBatchSize` is demoted to a secondary row cap
plus the DB read-page size. The rig's `MaxBatchSize = 16` was chosen as a
hand-computed byte proxy ("row-count-only against gRPC's 4 MB cap"), and that
rationale is now wrong everywhere it appeared — appsettings, Configuration.md,
the pair-replication runbook, and both docker-dev site-a services.

The VALUE stays 16, for a different and still-real reason: OplogStore /
SnapshotStreamer materialise a whole read page in memory *before* the
byte-budget split runs, so 16 x ~171 KB artifact chunk rows bounds that
transient allocation at ~2.7 MB. Documented as such, with `MaxBatchBytes`
added to both config tables.

CLAUDE.md records the pin and two deliberate non-adoptions: this repo does not
take ScadaBridge's conditional-registration + boot-time `DeregisterReplicated`
self-heal (OnReady registers all four tables unconditionally, and
LocalDbSetupTests pins that set), and consequently does not use
`baselineExistingRows` either — so enabling replication on a long-running
default-OFF node converges on subsequent writes, not on rows already in the
file. Both are behaviour changes, out of scope for a pin bump.

Verification: solution builds clean; full suite run (57 projects). All 66
LocalDb tests in Host.IntegrationTests green. One unrelated failure,
RoslynVirtualTagEvaluatorTests.Evaluate_racing_ClearCompiledScripts_never_
fails_with_disposed — a Roslyn evaluator disposal race with no LocalDb in its
path, whose own comment documents that its "at most one clear per evaluation"
assumption depends on thread-pool pressure. It passed 3/3 re-runs in isolation
and fails only under full-solution parallel load; pre-existing test-design
fragility, not a regression from this bump.

src/Server/ZB.MOM.WW.OtOpcUa.Host/appsettings.json

@@ -64,7 +64,8 @@
     "SyncListenPort": 0,
     "Replication": {
       "_comment": "Empty = passive/off. Set PeerAddress on exactly ONE node of the pair (the stream is bidirectional, so the other side still pushes its own deltas back). ApiKey must be BYTE-IDENTICAL on both nodes — the host interceptor fail-closes, so a typo silently stops convergence rather than degrading to unauthenticated. Supply it via ${secret:...} in production, never committed.",
-      "_MaxBatchSizeComment": "Row count, NOT bytes, against gRPC's 4 MB default message cap. Artifact chunk rows are ~171 KB base64, so keep this at 16 on the pair (16 x 171 KB ~= 2.7 MB worst case)."
+      "_MaxBatchSizeComment": "Secondary ROW-COUNT cap, and the DB read-page size, since LocalDb 0.2.0. The wire message is bounded by MaxBatchBytes (2 MB default, sized under gRPC's 4 MB cap), so this is no longer the hand-tuned byte proxy it once was. It still matters: OplogStore/SnapshotStreamer materialise a whole read page in memory BEFORE the byte-budget split runs, so keep it at 16 on the pair to bound that transient allocation (artifact chunk rows are ~171 KB base64, so 16 x 171 KB ~= 2.7 MB).",
+      "_MaxBatchBytesComment": "Primary cap on one outbound delta/snapshot message: summed serialized entry size, default 2 MB. Leave unset unless the gRPC message limit is retuned. A single row over budget is sent alone rather than stalling the stream."
     }
   },
   "Deployment": {