fix(cli): move LeetCode fetches to GraphQL and restore history from the profile

LeetCode's REST /api/* endpoints now answer a Cloudflare 403 to non-browser
clients, which broke the picker's problem index on an empty cache. The index
and descriptions now come from /graphql, and test/submit fold the signed-in
profile's submission history into the solutions table once a day, so a lost
db or a fresh clone recovers both orderings.

AGENTS.md

@@ -71,7 +71,11 @@ bun run test            # run ONE solution against LeetCode's judge (not a test
                         # files git sees as modified/untracked first, so Enter runs the
                         # one in progress; then most recently tested; stamped on exit 0)
 bun run submit          # submit ONE solution to LeetCode (uncommitted first, then newest
-                        # scaffold, nothing hidden; last_submitted stamped on exit 0)
+                        # scaffold, nothing hidden; last_submitted stamped on exit 0).
+                        # Both fold in the signed-in profile's submission history once
+                        # a day (leetcode-cli's keychain login; GraphQL only — LeetCode's
+                        # REST /api/* answers 403), so a lost db or fresh clone recovers
+                        # both orderings
 bun run sync            # work/1 → apps/docs/content/ pages + apps/docs/redirects.ts (/<num> short
                         # links; re-solves are never published)
 bun run videos          # docs pages with no `video:` frontmatter → NeetCode video per page