feat: add following and followers commands

Add two new commands to list users:
- `bird following` - list users that you (or another user) follow
- `bird followers` - list users that follow you (or another user)

Both commands support:
- `--user <userId>` to query another user's following/followers
- `-n <count>` to limit results
- `--json` for structured output

Uses Twitter's GraphQL Following/Followers endpoints with proper
feature flags and query ID rotation support.

src/lib/query-ids.json

@@ -3,5 +3,7 @@
   "CreateRetweet": "LFho5rIi4xcKO90p9jwG7A",
   "FavoriteTweet": "lI07N6Otwv1PhnEgXILM7A",
   "TweetDetail": "97JF30KziU00483E_8elBA",
-  "SearchTimeline": "M1jEez78PEfVfbQLvlWMvQ"
+  "SearchTimeline": "M1jEez78PEfVfbQLvlWMvQ",
+  "Following": "BEkNpEt5pNETESoqMsTEGA",
+  "Followers": "kuFUYP9eV1FPoEy4N-pi7w"
 }