Give ADR 0300 its place in to-be 53: the tracker's record is a log of operations (issue 508)

ADR 0300 was accepted with no home, so the knowledge base's whole-set rule fails and holds every rollout of mesh-knowledge.

03-DESIGN/01-to-be/53-the-issue-tracker.md

@@ -12,6 +12,7 @@ decisions:
   - "ADR 0285"
   - "ADR 0291"
   - "ADR 0294"
+  - "ADR 0300"
 ---
 
 # 53 — The issue tracker
@@ -267,6 +268,13 @@ what it depends on, and the issue is said ready when every fix it waits for is d
 - The values are optional keys of an issue's one JSON value: an issue kept before reads as having none, and the
   key-value store has no schema to migrate.
 
+## 10a. The record is a log of operations
+
+**The tracker's record is its log of operations, and its bucket is that log's fold** (ADR 0300, resting on ADR 0297):
+every write is one operation appended under the issue's number before the bucket is written; the bucket is rebuilt
+from the log on start; the events announce and the log is the audit trail; `list` answers from memory with a ranked
+search and a `before` cursor. Built under issues 501 and 502.
+
 ## 11. Whether the fix is delivered
 
 **An issue knows whether its fix is on the machines, as the delivery says it; delivered is not resolved, and a fix