Record whether a node is adopted and which modules were taken on it (hq ADR 0100)

internal/inventory/migrations/0029-a-node-is-adopted-or-converged.sql

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+-- A node is adopted or converged, and the mesh records which (novox/hq ADR 0100).
+--
+-- A machine already serving a predecessor's services is adopted: what is found on it is kept
+-- until its module is taken, and the firewall found on it stays in force. It stays adopted until
+-- the operator converges it. False by default, so every node that exists is converged, as it was.
+
+alter table node add column adopted boolean not null default false;
+-- When it was last made adopted, and when it last converged. Both kept: a node returned to adopted
+-- after converging is a different history from one that never converged.
+alter table node add column adopted_since timestamptz;
+alter table node add column converged_at timestamptz;
+
+-- The modules taken on a node: its cutover, the operator's act, done when the module's data has
+-- moved. A row per node and module, and it outlives the assignment on purpose -- unassigning a
+-- module does not un-take it, and what was taken stays taken when a node returns to adopted.
+create table taken (
+    node      uuid        not null references node(id) on delete cascade,
+    module    text        not null references module(name) on delete cascade,
+    taken_at  timestamptz not null default now(),
+    primary key (node, module)
+);