test(server): drop the unreadable-collection item-context test, vacuous since the brief reuses the dashboard's predicates (PLAN-3598 slice (b))

It pinned a decision the brief's own lifecycle cache made (an undecodable
schema is open work, not reference). b350f7f09 deleted that cache: the
brief now asks isItemDone and isReferenceCollection, which never consult
whether the schema decoded (reference-ness reads settings; a zero schema
compares status against the default terminal values), so no change to the
brief could make it fail. It also failed on Postgres in setup: the json
schema column refuses the non-JSON string it wrote (22P02).

Claude-Session: https://claude.ai/code/session_01Q9WssCjFuHjSfLABoW4tmS

internal/server/plan3598_item_context_test.go

@@ -360,42 +360,3 @@ func TestPLAN3598_ItemContextReferenceBlockerAgreesWithDashboard(t *testing.T) {
 		}
 	})
 }
-
-// A blocker whose collection's schema cannot be read still raises
-// open_blocker: isItemDone, the dashboard's predicate, reads an unparseable
-// schema as zero-valued, so an open status stays open.
-func TestPLAN3598_ItemContextUnreadableCollectionStaysOpenWork(t *testing.T) {
-	forEachDialect(t, func(t *testing.T, d store.DriverType) {
-		f := newCtxFixture(t, d)
-		coll, err := f.srv.store.CreateCollection(f.wsID, models.CollectionCreate{
-			Name:   "Oddities",
-			Schema: `{"fields":[{"key":"status","label":"Status","type":"select","options":["open","done"],"terminal_options":["done"]}]}`,
-		})
-		if err != nil {
-			t.Fatal(err)
-		}
-		odd, err := f.srv.store.CreateItem(f.wsID, coll.ID, models.ItemCreate{Title: "Ctx odd blocker", Fields: `{"status":"open"}`})
-		if err != nil {
-			t.Fatal(err)
-		}
-		if _, err := f.srv.store.CreateItemLink(f.wsID, models.ItemLinkCreate{TargetID: f.task.ID, LinkType: models.ItemLinkTypeBlocks}, odd.ID); err != nil {
-			t.Fatal(err)
-		}
-		if _, err := f.srv.store.DB().Exec(f.srv.store.D().Rebind(`UPDATE collections SET schema = ? WHERE id = ?`), "not json", coll.ID); err != nil {
-			t.Fatalf("corrupt schema: %v", err)
-		}
-		resp, code, body := f.context(f.ownerTok, "?intent=implement")
-		if resp == nil {
-			t.Fatalf("status %d: %s", code, body)
-		}
-		found := false
-		for _, c := range resp.Conflicts {
-			for _, r := range c.Refs {
-				found = found || (c.Kind == "open_blocker" && r == odd.Ref)
-			}
-		}
-		if !found {
-			t.Errorf("a blocker in an unreadable collection should stay open work: %+v", resp.Conflicts)
-		}
-	})
-}