ADR 0136: a step gates its module, not the machine

ADR 0135 made a step something the mesh derives for any module that prepares its state, which turned
ADR 0052's reach into a fault: a module whose database is briefly unreachable would stop every module
declared after it on that machine — the fault issue 011 already removed for every other shape, and
the reason the catalogue migrates itself at start rather than in a step.

A step now stops the rest of its own module and nothing else; an action still gates the machine,
because genesis is a row of them and they belong to no module. What was not attempted is reported as
skipped rather than left to be inferred from silence.

03-DESIGN/01-to-be/32-what-a-module-declares.md

@@ -13,6 +13,7 @@ decisions:
   - 02-DECISIONS/0083-one-push-leaves-the-mesh-consistent.md
   - 02-DECISIONS/0129-a-seat-carries-the-protocol-of-its-role.md
   - 02-DECISIONS/0135-a-module-version-prepares-its-state-before-it-runs.md
+  - 02-DECISIONS/0136-a-step-gates-its-module-not-the-machine.md
   - 02-DECISIONS/0134-the-mesh-says-what-it-applied.md
 ---
 
@@ -264,7 +265,9 @@ queue of superseded ones, and a replayed older one is refused by sequence.
 its state to the shape that version needs — the same vocabulary as the entrypoints it declares for its
 tools and its provisioner, and nothing about how a machine runs it. The mesh runs that entrypoint as it
 runs the module's own code, to completion, in the module's own context, and a version whose preparation
-did not succeed does not run: the rollout stops at the first machine that did not take it
+did not succeed does not run: the step gates that module and nothing else on the machine
+([ADR 0136](../../02-DECISIONS/0136-a-step-gates-its-module-not-the-machine.md)), and the rollout stops
+at the first machine that did not take it
 ([ADR 0135](../../02-DECISIONS/0135-a-module-version-prepares-its-state-before-it-runs.md), superseding
 [ADR 0133](../../02-DECISIONS/0133-a-module-owns-its-migrations-and-the-mesh-owns-when-they-run.md)).
 Once per state, and the mesh derives what a state is: a consumer is a module on a machine, so what the