Trim NOTEBOOK open tasks to reflect task/done/ sweep

13 task files have been moved to task/done/ after verifying
their implementation in current code. Only the downstream
riddl-models sbt-riddl upgrade remains genuinely open in this
repo's task/.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: reid-spencer

NOTEBOOK.md

@@ -24,12 +24,12 @@ in sync with origin. No work-in-progress; no stashes.
 
 ## Open Tasks in `task/`
 
-- `error-location-end-of-line.md`
-- `sbt-riddl-validate-on-compile-fix.md`
-- `scope-based-parsing-api.md`
-- `optimize-treepass-performance.md`
-- `optimize-resolutionpass-performance.md`
-- `upgrade-sbt-riddl-1.15.4.md`
+- `upgrade-sbt-riddl-1.15.4.md` — downstream task for
+  riddl-models; sbt-riddl in this repo is already past 1.15.4
+  via the normal release cadence
+
+Completed task files live in `task/done/` (gitignored, local
+hygiene only).
 
 ## Active Work Queue