Establish Railiance architecture home

docs/adr/ADR-0004-first-wave-reef-rollout.md

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+# ADR-0004: First-Wave `reef-*` Rollout
+
+Date: 2026-07-25
+Status: Accepted
+
+## Context
+
+Railiance now has a reef model, but it needs a concrete first rollout.
+
+The current substrate reality is not uniform:
+
+- Railiance01 is the clearest new-workload home
+- CoulombCore is still active but transitional
+- the workstation role is operator edge compute rather than server substrate
+
+At the same time, S1 ownership is ambiguous because `railiance-hosts` and
+`railiance-infra` duplicate each other.
+
+## Decision
+
+The first-wave reef rollout is:
+
+1. `reef-railiance01`
+2. `reef-coulombcore`
+3. `reef-ops-workstations`
+
+`railiance-infra` is the canonical S1 ownership repo going forward.
+
+`railiance-hosts` is treated as predecessor or duplicate state to be retired,
+frozen, or reduced later rather than as a second canonical S1 architecture home.
+
+## Consequences
+
+### Positive
+
+- Railiance gets a primary home-reef seed without waiting for a multi-node
+  future.
+- Transitional CoulombCore reality is acknowledged without being treated as the
+  long-term preferred production pattern.
+- Operator edge compute is modeled without defaulting to one repo per machine.
+- Reef planning now rests on one canonical S1 ownership line.
+
+### Required Follow-On Work
+
+- Create repo-local rollout work for the first reef repos.
+- Decide whether Railiance01 later remains a singleton reef or becomes part of
+  a grouped home reef.
+- Plan the `railiance-hosts` cleanup direction relative to `railiance-infra`.
+
+### Constraints
+
+- Multi-rail reefs are acceptable early, especially on transitional substrates.
+- Production-grade separation should still prefer clearer purpose and primary
+  rail boundaries as criticality rises.
+- Transitional substrate nicknames should remain provisional until the pattern
+  is stable enough to canonize.
+
+## Notes
+
+This ADR chooses the first rollout set. It does not require that every future
+substrate be modeled the same way.