docs: close out serenity migration cleanup lane

docs/planning/SERENITY_MAJORITY_MIGRATION_PLAN.md

@@ -12,6 +12,7 @@ Completed live:
 - `Hawser` + `dockersocket` verified live and healthy on Serenity
 - `Notifiarr` re-evaluated against live PD headroom and intentionally left on Serenity for now
 - `netdata` re-evaluated and kept on Serenity for now as host-local monitoring, not as an early migration target
+- closeout check: no remaining open Serenity-specific Kanban cards exist from the completed cleanup/planning wave; only the documented planned/blocked future lanes remain
 
 Current blockers verified live:
 - PD is still RAM-constrained (`31 GiB total`, `27 GiB used`, `2.3 GiB free` at check time)
@@ -133,7 +134,7 @@ Use this as the working card map.
 ### Epic A — Immediate cleanup and intention-locking
 
 #### A1. Retire Wizarr
-Status: ready
+Status: completed 2026-05-26
 Depends on: none
 
 Acceptance criteria:
@@ -143,7 +144,7 @@ Acceptance criteria:
 - rollback expectation is explicitly "rebuild if needed later," not "preserve migrated state"
 
 #### A2. Document Hawser + dockersocket as protected keepers
-Status: ready
+Status: completed 2026-05-26
 Depends on: none
 
 Acceptance criteria:
@@ -152,7 +153,7 @@ Acceptance criteria:
 - any later rehome/removal must be paired with a replacement Dockhand management path
 
 #### A3. Decide whether netdata remains worth keeping
-Status: ready
+Status: completed 2026-05-26
 Depends on: none
 
 Acceptance criteria:
@@ -212,7 +213,7 @@ Acceptance criteria:
 ### Epic C — Optional tiny near-term moves
 
 #### C1. Re-evaluate Notifiarr against live PD headroom
-Status: ready
+Status: completed 2026-05-26
 Depends on: none
 
 Acceptance criteria: