Five sequential plans: foundations (deferred_bindings, attach.Store,
lagoon.Date/TimeOfDay, purge), cabana datepicker and fileupload, relation
child CRUD with deferral, admin SPA, and unit and security tests.
Adds D-22..D-24 from the plan-count checkpoint and the pattern map.
Plan checker iteration 1 flagged unresolved research questions and a
missing decision note for golang.org/x/net/html. D-18 approves x/net/html
for the partial sanitizer; D-19 fixes the Discogs widget fill to
[year, format]. STATE marks the phase ready to execute.
