fix: spread random usernames so adjacent YouTube comments stop sharing suffixes

The earlier DJB2 hash produced near-identical bucket positions for seeds that only differed in the trailing index, which is why ten consecutive fetched comments often ended up with the same noun and the same _official or _skater suffix. Replaces the hash with FNV-1a plus three independent mix steps and almost doubles both word lists so the rail now shows visibly distinct authors.

frontend/src/utils/toxicity.ts

@@ -57,6 +57,10 @@ const ADJECTIVES = [
   "brave", "fuzzy", "shiny", "sleepy", "quick", "noble", "loud", "humble",
   "stormy", "sunny", "rainy", "frosty", "spicy", "salty", "sweet", "crazy",
   "mighty", "silent", "epic", "cosmic", "rusty", "neon", "wandering", "lone",
+  "electric", "atomic", "midnight", "golden", "silver", "crimson", "violet", "azure",
+  "ancient", "feral", "tidal", "lunar", "solar", "ember", "frost", "iron",
+  "velvet", "wicked", "groovy", "funky", "chill", "vibrant", "moody", "savage",
+  "tropical", "alpine", "urban", "rogue", "stellar", "nomadic", "boreal", "obsidian",
 ];
 
 const NOUNS = [
@@ -64,23 +68,47 @@ const NOUNS = [
   "lynx", "shark", "raven", "viper", "phoenix", "dragon", "jaguar", "koala",
   "moose", "lion", "owl", "octopus", "rabbit", "hawk", "badger", "robin",
   "cosmonaut", "drifter", "ninja", "wizard", "rider", "pilot", "skater", "gamer",
+  "barista", "hacker", "painter", "poet", "sailor", "ranger", "archer", "dancer",
+  "chef", "cyclist", "writer", "drummer", "diver", "climber", "biker", "florist",
+  "comet", "nebula", "nova", "pulsar", "quasar", "asteroid", "meteor", "orbiter",
+  "knight", "monk", "scribe", "merchant", "wanderer", "voyager", "explorer", "pirate",
 ];
 
-const SUFFIXES = ["", "_", "_", "_yt", "_hd", "_real", "99", "01", "_xd", "_v2", "_official", ""];
+const SUFFIXES = [
+  "", "", "", "", "",
+  "_", "_x", "_yt", "_hd", "_real", "_official", "_tv", "_live", "_xd", "_v2",
+  "99", "01", "07", "23", "42",
+  "_irl", "_pro",
+];
+
+function hashString(str: string): number {
+  let h = 0x811c9dc5;
+  for (let i = 0; i < str.length; i++) {
+    h ^= str.charCodeAt(i);
+    h = Math.imul(h, 0x01000193) >>> 0;
+  }
+  return h >>> 0;
+}
+
+function mix(h: number, salt: number): number {
+  let x = (h ^ Math.imul(salt + 1, 0x85ebca6b)) >>> 0;
+  x = Math.imul(x ^ (x >>> 13), 0xc2b2ae35) >>> 0;
+  return (x ^ (x >>> 16)) >>> 0;
+}
 
 /**
  * Generate a YouTube-style random username, deterministic per seed.
+ * Three independent hash mixes pick adjective, noun, and suffix so that
+ * seeds that share a prefix (e.g. `yt-VIDEOID-0`, `yt-VIDEOID-1`) still
+ * produce visibly different usernames.
  */
 export function randomUsername(seed: string | number | undefined | null): string {
   const str = seed == null ? "anon" : String(seed);
-  let hash = 5381;
-  for (let i = 0; i < str.length; i++) {
-    hash = ((hash << 5) + hash + str.charCodeAt(i)) >>> 0;
-  }
-  const adj = ADJECTIVES[hash % ADJECTIVES.length] ?? "anon";
-  const noun = NOUNS[Math.floor(hash / 32) % NOUNS.length] ?? "user";
-  const suffix = SUFFIXES[Math.floor(hash / 1024) % SUFFIXES.length] ?? "";
+  const base = hashString(str);
+  const adj = ADJECTIVES[mix(base, 1) % ADJECTIVES.length] ?? "anon";
+  const noun = NOUNS[mix(base, 2) % NOUNS.length] ?? "user";
+  const suffix = SUFFIXES[mix(base, 3) % SUFFIXES.length] ?? "";
   const needsNum = suffix === "" || suffix.endsWith("_");
-  const num = needsNum ? String(hash % 1000) : "";
+  const num = needsNum ? String(mix(base, 4) % 1000) : "";
   return `${adj}_${noun}${suffix}${num}`;
 }