chore: add pre-commit hooks, tighten ESLint, activate Sentry DSN, publish CI coverage (Phase 1)

- Install husky v9 + lint-staged: pre-commit runs eslint --fix and prettier on staged files
- Tighten ESLint base config: no-console→error, ban-ts-comment (ts-ignore banned, ts-expect-error with description allowed), reportUnusedDisableDirectives→error
- Migrate web app from deprecated `next lint` to `eslint src/` with flat config and react-hooks plugin
- Convert all 5 @ts-ignore to @ts-expect-error with descriptions, remove stale disable comments
- Add NEXT_PUBLIC_SENTRY_DSN to docker-compose.prod.yml and .env.example
- Add coverage artifact upload step to CI test job
- Pre-existing violations (102 warnings) downgraded to warn in web config for Phase 2 cleanup

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/components/dashboard/widgets/TaskWidget.tsx

@@ -6,7 +6,6 @@ import { trpc } from "~/lib/trpc/client.js";
 import type { WidgetProps } from "~/components/dashboard/widget-registry.js";
 import { TaskCard } from "~/components/notifications/TaskCard.js";
 
-// eslint-disable-next-line @typescript-eslint/no-unused-vars
 export function TaskWidget(_props: Partial<WidgetProps> = {}) {
   const utils = trpc.useUtils();
 
@@ -15,10 +14,13 @@ export function TaskWidget(_props: Partial<WidgetProps> = {}) {
     { staleTime: 30_000, placeholderData: (prev) => prev },
   );
 
-  const { data: taskCounts, isLoading: loadingCounts } = trpc.notification.taskCounts.useQuery(undefined, {
-    staleTime: 30_000,
-    placeholderData: (prev) => prev,
-  });
+  const { data: taskCounts, isLoading: loadingCounts } = trpc.notification.taskCounts.useQuery(
+    undefined,
+    {
+      staleTime: 30_000,
+      placeholderData: (prev) => prev,
+    },
+  );
 
   const updateTaskStatus = trpc.notification.updateTaskStatus.useMutation({
     onSuccess: () => {
@@ -30,7 +32,10 @@ export function TaskWidget(_props: Partial<WidgetProps> = {}) {
   });
 
   function handleStatusChange(id: string, status: string) {
-    updateTaskStatus.mutate({ id, status: status as "OPEN" | "IN_PROGRESS" | "DONE" | "DISMISSED" });
+    updateTaskStatus.mutate({
+      id,
+      status: status as "OPEN" | "IN_PROGRESS" | "DONE" | "DISMISSED",
+    });
   }
 
   const openCount = (taskCounts?.open ?? 0) + (taskCounts?.inProgress ?? 0);