test: make the real-Redis TTL tests runnable against a rediss:// URL

The two REDIS_TEST_URL-gated tests could never have passed as written: a
unit-test binary never runs main(), so no rustls crypto provider was
installed and the TLS handshake to a rediss:// URL panicked before any
command was sent. Install the provider in a helper inside the test module
and reuse the same call main.rs already makes.

Also fix a key-construction typo in the retry/DLQ test: the retry counter
key embeds the message id, not the run id.

Verified against the live Upstash instance:
  REDIS_TEST_URL=rediss://... cargo test --locked -- --ignored ttl
  ttl_claim_dedup_sets_the_exactly_requested_expiry ... ok
  ttl_consent_and_retry_landing_on_real_redis ... ok

src/main.rs

@@ -207,7 +207,7 @@ async fn main() -> Result<(), error::BotError> {
     Ok(())
 }
 
-fn install_rustls_provider() -> bool {
+pub(crate) fn install_rustls_provider() -> bool {
     rustls::crypto::ring::default_provider()
         .install_default()
         .is_ok()

src/state.rs

@@ -1653,6 +1653,16 @@ mod real_redis_ttl_tests {
         format!("{}:{}", std::process::id(), unix_now())
     }
 
+    /// Unit-test binaries never run `main()`, so no rustls crypto provider is
+    /// installed and the TLS handshake to a `rediss://` URL panics before any
+    /// command is sent. Mirror the one-time setup in `main.rs`.
+    fn require_tls_provider() {
+        assert!(
+            crate::install_rustls_provider(),
+            "rustls needs a crypto provider before any Redis TLS client"
+        );
+    }
+
     #[tokio::test]
     #[ignore = "requires REDIS_TEST_URL pointing at a reachable Redis"]
     async fn ttl_claim_dedup_sets_the_exactly_requested_expiry() {
@@ -1660,6 +1670,7 @@ mod real_redis_ttl_tests {
             eprintln!("skipped: REDIS_TEST_URL is not configured");
             return;
         };
+        require_tls_provider();
         let state = RedisState::connect(url.to_str().expect("valid utf8 REDIS_TEST_URL"))
             .await
             .expect("REDIS_TEST_URL must be reachable");
@@ -1699,6 +1710,7 @@ mod real_redis_ttl_tests {
             eprintln!("skipped: REDIS_TEST_URL is not configured");
             return;
         };
+        require_tls_provider();
         let state = RedisState::connect(url.to_str().expect("valid utf8 REDIS_TEST_URL"))
             .await
             .expect("REDIS_TEST_URL must be reachable");