docs(10.1): record D-18/D-19, resolve research questions, add 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.

.planning/phases/10.1-runtime-admin-extension-point/10.1-03-PLAN.md

@@ -29,7 +29,7 @@ must_haves:
   truths:
     - "Per D-01, D-03 and D-11, the Albums list declares `headerPartial: stats` in config_list.yaml and GET /plytadmin/api/v1/golem15/fonoteka/albums/partials/stats returns a statistics strip for the admin's own collection: the total, one item per stored format with count above zero in getFormatOptions order, and a no-shelf item only when that count is above zero."
     - "Per D-10, every stats count runs through albumsAdminController.scopeAlbums, and the view model is a curated struct of labels and integers, never an Album model; an admin bound to one collection never sees another collection's counts."
-    - "Per D-01, D-02, D-04, D-06 and D-07, the Albums form declares a `year` number field after `shelf` and a last, full-width `discogs` widget (widget golem15-fonoteka-discogs-lookup, action discogsLookup, fill [year, format]) that renders on create and update; its stub action answers the message key golem15.fonoteka::lang.discogs.stub_filled with fill {year: 1977, format: \"LP\"} and makes no outbound call; Phase 14 replaces the stub."
+    - "Per D-01, D-02, D-04, D-06, D-07 and D-19, the Albums form declares a `year` number field after `shelf` and a last, full-width `discogs` widget (widget golem15-fonoteka-discogs-lookup, action discogsLookup, fill [year, format]) that renders on create and update; its stub action answers the message key golem15.fonoteka::lang.discogs.stub_filled with fill {year: 1977, format: \"LP\"} and makes no outbound call; Phase 14 replaces the stub."
     - "Per D-12, the Albums toolbar declares buttons [create, delete, discogsSync]; the discogsSync stub answers golem15.fonoteka::lang.discogs.stub_not_implemented and changes nothing; both Discogs actions require the existing Winter permission golem15.fonoteka.access_albums, so a limited admin gets 403."
     - "Per D-13 to D-16, the controller declares assets/js/discogs-lookup.js and assets/css/albums.css through AdminJS/AdminCSS, both embedded in the plugin AdminFS and served under /plytadmin/assets/golem15/fonoteka/ with a JavaScript or CSS content type; the element is plain JS with no import, no user-facing string, no network request and no cookie or storage access."
     - "UI consideration (populated S1 Albums stats strip): one .summer-stats card shows the total, then formats with count above zero in option order, then No shelf when above zero, each a 13px muted label under a 20px/600 value."
@@ -113,7 +113,7 @@ Tests pinning the current Albums shape: admin_albums_test.go (`len(schema.Fields
 ## Planning notes
 
 - Spec-less probe fallback skipped: no requirement IDs were mapped for Phase 10.1 before this planning run; ADMIN-07 is introduced by it. Truths come from CONTEXT D-01..D-17 and the UI-SPEC "Application proof" rows.
-- Discretion resolved per UI-SPEC and RESEARCH Open Questions 1 and 3: stats show the total, per-format counts and no-shelf; the widget fills `[year, format]`, which needs the new `year` field; action names `discogsLookup` and `discogsSync`; both reuse `golem15.fonoteka.access_albums` (Pitfall 12, no Winter catalog divergence); the widget renders on create and update.
+- Discretion resolved per UI-SPEC and RESEARCH Open Questions 1 and 3: stats show the total, per-format counts and no-shelf; the widget fills `[year, format]`, which needs the new `year` field (D-19); action names `discogsLookup` and `discogsSync`; both reuse `golem15.fonoteka.access_albums` (Pitfall 12, no Winter catalog divergence); the widget renders on create and update.
 - Albums has no real form partial; the form `type: partial` path is proven by the acme fixture in 10.1-01 (D-03 discretion).
 - Tests here are smoke tests; the full Albums acceptance test is 10.1-04 (CLAUDE.md rule 3).