feat(providers): add DeepMyst as OpenAI-compatible provider (zeroclaw-labs#4103)

Register DeepMyst (https://deepmyst.com) as an OpenAI-compatible
provider with Bearer auth and DEEPMYST_API_KEY env var support.
Aliases: "deepmyst", "deep-myst".

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

src/providers/mod.rs

@@ -909,6 +909,7 @@ fn resolve_provider_credential(name: &str, credential_override: Option<&str>) ->
         "ovhcloud" | "ovh" => vec!["OVH_AI_ENDPOINTS_ACCESS_TOKEN"],
         "astrai" => vec!["ASTRAI_API_KEY"],
         "avian" => vec!["AVIAN_API_KEY"],
+        "deepmyst" | "deep-myst" => vec!["DEEPMYST_API_KEY"],
         "llamacpp" | "llama.cpp" => vec!["LLAMACPP_API_KEY"],
         "sglang" => vec!["SGLANG_API_KEY"],
         "vllm" => vec!["VLLM_API_KEY"],
@@ -1502,6 +1503,9 @@ fn create_provider_with_url_and_options(
         "avian" => Ok(compat(OpenAiCompatibleProvider::new(
             "Avian", "https://api.avian.io/v1", key, AuthStyle::Bearer,
         ))),
+        "deepmyst" | "deep-myst" => Ok(compat(OpenAiCompatibleProvider::new(
+            "DeepMyst", "https://api.deepmyst.com/v1", key, AuthStyle::Bearer,
+        ))),
 
         // ── Cloud AI endpoints ───────────────────────────────
         "ovhcloud" | "ovh" => Ok(Box::new(openai::OpenAiProvider::with_base_url(
@@ -2875,6 +2879,20 @@ mod tests {
         assert!(create_provider("avian", Some("sk-avian-test")).is_ok());
     }
 
+    #[test]
+    fn factory_deepmyst() {
+        assert!(create_provider("deepmyst", Some("key")).is_ok());
+        assert!(create_provider("deep-myst", Some("key")).is_ok());
+    }
+
+    #[test]
+    fn resolve_provider_credential_deepmyst_env() {
+        let _env_lock = env_lock();
+        let _guard = EnvGuard::set("DEEPMYST_API_KEY", Some("dm-test-key"));
+        let resolved = resolve_provider_credential("deepmyst", None);
+        assert_eq!(resolved, Some("dm-test-key".to_string()));
+    }
+
     // ── Custom / BYOP provider ─────────────────────────────
 
     #[test]