Stabilize provider compatibility integration verification

Keep integrated G008 provider changes formatted and compile-ready so worker follow-up commits can merge against a clean leader baseline.

Constraint: G008 provider verification must pass before ultragoal checkpointing.
Confidence: high
Scope-risk: narrow
Directive: Keep provider compatibility follow-ups rebased on this formatted baseline before retrying failed cherry-picks.
Tested: cargo test --manifest-path rust/Cargo.toml -p api providers:: -- --nocapture; cargo test --manifest-path rust/Cargo.toml -p api --test openai_compat_integration -- --nocapture --test-threads=1
Not-tested: full workspace clippy; known pre-existing runtime policy_engine LaneContext clippy warning remains outside this change.

Co-authored-by: OmX <omx@oh-my-codex.dev>

rust/crates/api/src/lib.rs

@@ -22,8 +22,8 @@ pub use providers::anthropic::{AnthropicClient, AnthropicClient as ApiClient, Au
 pub use providers::openai_compat::{
     build_chat_completion_request, check_request_body_size, estimate_request_body_size,
     flatten_tool_result_content, is_reasoning_model, model_rejects_is_error_field,
-    model_requires_reasoning_content_in_history, translate_message,
-    OpenAiCompatClient, OpenAiCompatConfig,
+    model_requires_reasoning_content_in_history, translate_message, OpenAiCompatClient,
+    OpenAiCompatConfig,
 };
 pub use providers::{
     detect_provider_kind, max_tokens_for_model, max_tokens_for_model_with_override,

rust/crates/api/src/providers/mod.rs

@@ -851,7 +851,10 @@ mod tests {
     fn provider_capability_matrix_snapshots_openai_compat_differences() {
         let openai = provider_capabilities_for_model("openai/gpt-4.1-mini");
         assert_eq!(openai.provider, ProviderKind::OpenAi);
-        assert_eq!(openai.wire_protocol, ProviderWireProtocol::OpenAiChatCompletions);
+        assert_eq!(
+            openai.wire_protocol,
+            ProviderWireProtocol::OpenAiChatCompletions
+        );
         assert_eq!(openai.auth_env, "OPENAI_API_KEY");
         assert_eq!(openai.streaming_usage, ProviderFeatureSupport::Supported);
         assert_eq!(openai.reasoning_effort, ProviderFeatureSupport::Supported);
@@ -872,7 +875,10 @@ mod tests {
 
         let anthropic = provider_capabilities_for_model("claude-sonnet-4-6");
         assert_eq!(anthropic.provider, ProviderKind::Anthropic);
-        assert_eq!(anthropic.wire_protocol, ProviderWireProtocol::AnthropicMessages);
+        assert_eq!(
+            anthropic.wire_protocol,
+            ProviderWireProtocol::AnthropicMessages
+        );
         assert_eq!(anthropic.prompt_cache, ProviderFeatureSupport::Supported);
         assert_eq!(
             anthropic.custom_parameters,
@@ -911,9 +917,9 @@ mod tests {
         assert!(codes.contains(&"deepseek_v4_reasoning_history"));
         assert!(codes.contains(&"web_search_passthrough_tool"));
         assert!(codes.contains(&"web_fetch_passthrough_tool"));
-        assert!(diagnostics.iter().any(|diagnostic| diagnostic
-            .action
-            .contains("provider adapter")));
+        assert!(diagnostics
+            .iter()
+            .any(|diagnostic| diagnostic.action.contains("provider adapter")));
     }
 
     #[test]

rust/crates/api/src/providers/openai_compat.rs

@@ -1608,6 +1608,7 @@ mod tests {
         ToolChoice, ToolDefinition, ToolResultContentBlock,
     };
     use serde_json::json;
+    use std::collections::BTreeMap;
     use std::sync::{Mutex, OnceLock};
 
     #[test]