docs(memory): add naming and maintenance guidance

memory/2026-03-11.md

@@ -42,3 +42,4 @@
 - Be more disciplined about using the daily note as the default inbox and promoting only durable truths into `MEMORY.md`.
 - Avoid adding new one-off memory files unless the topic is truly long-lived.
 - Keep top-level `memory/` mostly reserved for daily notes; use subfolders for topical material.
+- Use a light weekly memory-maintenance pass during heartbeats instead of waiting for clutter to build up.

memory/README.md

@@ -47,6 +47,16 @@ When in doubt:
 2. later promote durable truths into `../MEMORY.md`
 3. only create a named note when the topic genuinely needs a long-lived home
 
+Create a named note when:
+- the topic will span multiple sessions
+- it needs to collect evidence, commands, or findings over time
+- it is likely to be reused as a reference later
+
+Prefer the daily note when:
+- it was a one-off conversation
+- it was a tiny fix or validation
+- the note would otherwise become a small orphan file
+
 ## Cleanup guidance
 
 If top-level `memory/` starts filling with non-daily files again: