Docs: record the FX-drain indicator in COMPLETED.md

docs/COMPLETED.md

@@ -1701,8 +1701,28 @@ the FX reclaim span before REAPER runs the command so the switch's own undo poin
 mints first rather than being caught mid-drain.
 
 **Left open:** `fxReclaimActivity()` — added in the fourth wave so a UI indicator
-could paint the drain's direction — shipped with no caller; a separate,
+could paint the drain's direction — shipped with no caller; the caller landed in
-not-yet-merged branch supplies one. `src/shell/view/CLAUDE.md` still carries a
+the FX-drain indicator entry below. `src/shell/view/CLAUDE.md` still carries a
 `[verify — DAW]` note on whether a redo can re-strand a track (rebuilding the
 pre-switch `view_state`, which carries no snapshot for a track that reads parked)
 — unresolved.
+
+### FX-drain indicator — the busy cursor and footer readout that give `fxReclaimActivity()` its caller
+
+Merged to `dev` as `ae305b6`, then `3fa4d10`. The background FX-reclaim drain the
+mode-switch redesign above left silent now paints: a busy cursor over the bank
+panel plus a footer readout that pre-empts the per-mode track count while the
+drain is moving, both driven off `fxReclaimActivity()`. `src/core/ui/` gained its
+own three-state `FxDrainState { Idle, Online, Offline }` enum, since `core/` may
+not include a shell header; the one map between it and the shell's
+`FxReclaimActivity` lives in `panel_input`'s `drainStateNow`. Online reads
+"restoring FX", Offline reads "parking FX" — both signed off by Daniel.
+
+Three things are unverified, as the tree marks them: whether REAPER's docker
+routes `WM_SETCURSOR` to the docked child dialog at all is `[verify — DAW]` in
+the code — the premise the whole Windows half of the indicator rests on.
+`IDC_APPSTARTING` is Windows-only; SWELL ships no equivalent, so on mac/Linux the
+footer readout is the whole indicator. And the readout's fit in the footer's
+count box is bounded only by a character count, not a real pixel width, since a
+pure test can't measure the proportional font without pulling shell drawing into
+`core/ui`; overflow end-ellipsizes rather than breaking layout.