refactor: fix remaining P2 architecture issues

Fix P2-6: proxy.ts now uses Permissions constants instead of hardcoded strings

Fix P2-7: useA11yId file no longer exists (use-aria-live.ts already in hooks/)

Fix P2-8: schema.ts section numbering reordered to continuous 1-24

Fix P2-11: announcements dead code void wasPublished already removed

Fix P2-17: app-sidebar.tsx uses hasRole() instead of permission-based role inference

Fix P2-18: scheduling/actions.ts removes trailing re-export of data-access; 4 pages now import directly from data-access

Sync architecture docs 004 and 005

src/app/(dashboard)/admin/scheduling/auto/page.tsx

@@ -3,7 +3,7 @@ import { CalendarClock, ClipboardList, Settings2 } from "lucide-react"
 
 import { Button } from "@/shared/components/ui/button"
 import { EmptyState } from "@/shared/components/ui/empty-state"
-import { getAdminClassesForScheduling } from "@/modules/scheduling/actions"
+import { getAdminClassesForScheduling } from "@/modules/scheduling/data-access"
 import { AutoSchedulePanel } from "@/modules/scheduling/components/auto-schedule-panel"
 
 export const dynamic = "force-dynamic"

src/app/(dashboard)/admin/scheduling/changes/page.tsx

@@ -6,7 +6,7 @@ import { EmptyState } from "@/shared/components/ui/empty-state"
 import {
   getAdminClassesForScheduling,
   getScheduleChanges,
-} from "@/modules/scheduling/actions"
+} from "@/modules/scheduling/data-access"
 import { ScheduleChangeList } from "@/modules/scheduling/components/schedule-change-list"
 import { ScheduleConflictsView } from "@/modules/scheduling/components/schedule-conflicts-view"
 import type { ScheduleChangeStatus } from "@/modules/scheduling/types"

src/app/(dashboard)/admin/scheduling/rules/page.tsx

@@ -4,7 +4,7 @@ import { EmptyState } from "@/shared/components/ui/empty-state"
 import {
   getAdminClassesForScheduling,
   getSchedulingRules,
-} from "@/modules/scheduling/actions"
+} from "@/modules/scheduling/data-access"
 import { SchedulingRulesForm } from "@/modules/scheduling/components/scheduling-rules-form"
 
 export const dynamic = "force-dynamic"

src/app/(dashboard)/teacher/schedule-changes/page.tsx

@@ -6,7 +6,7 @@ import {
   getAdminClassesForScheduling,
   getScheduleChanges,
   getTeachersForScheduling,
-} from "@/modules/scheduling/actions"
+} from "@/modules/scheduling/data-access"
 import { ScheduleChangeForm } from "@/modules/scheduling/components/schedule-change-form"
 import { ScheduleChangeList } from "@/modules/scheduling/components/schedule-change-list"