Fix random example: mix nanos with PID for better distribution

The previous seed (raw nanos % 20) produced the same index on
consecutive runs. XOR-shift nanos and add PID for variety.

Bump to 0.0.20.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JessyTsui

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cerul"
-version = "0.0.19"
+version = "0.0.20"
 edition = "2021"
 description = "Official Cerul CLI - search video knowledge from your terminal"
 license = "MIT"

src/main.rs

@@ -191,10 +191,13 @@ const EXAMPLE_QUERIES: &[&str] = &[
 
 fn pick_example_query() -> &'static str {
     use std::time::{SystemTime, UNIX_EPOCH};
-    let seed = SystemTime::now()
+    let nanos = SystemTime::now()
         .duration_since(UNIX_EPOCH)
         .unwrap_or_default()
-        .as_nanos() as usize;
+        .as_nanos();
+    // Mix bits for better distribution: XOR high and low, add PID
+    let pid = std::process::id() as u128;
+    let seed = ((nanos ^ (nanos >> 17)).wrapping_add(pid)) as usize;
     EXAMPLE_QUERIES[seed % EXAMPLE_QUERIES.len()]
 }