fix: harden openai-compatible provider, approval replay, and embeddings defaults (#237)

* fix: harden openai-compatible tool flow and local defaults

* fix: close approval replay gaps and harden openai-compatible flow

* fix: address review feedback and code improvements (takeover #112)

- Make ChatCompletionResponse.id Optional<String> to handle providers
  that omit or null the field
- Propagate HTTP client builder errors instead of silently dropping
  timeout configuration (openai_compatible_chat, nearai_chat)
- Add EMBEDDING_DIMENSION env var with smart per-model defaults instead
  of hardcoding 768/1536 everywhere
- Remove duplicated dimension inference logic from main.rs

Co-Authored-By: panosAthDBX <[email protected]>
Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: harden src/llm/ module from crate audit findings

- Replace 9x .expect() on RwLock with graceful poison recovery
  (nearai.rs: 7, nearai_chat.rs: 2) — eliminates production panics
- Propagate HTTP client builder errors in nearai.rs instead of
  silently dropping timeout config (NearAiProvider::new now returns Result)
- Make nearai_chat ChatCompletionResponse.id Optional<String>
  (mirrors openai_compatible_chat.rs fix for providers that omit id)
- Make nearai_chat usage fields optional with defensive parse_usage()
  helper (was required u32 fields that crash on null/missing)
- Truncate error responses to 512 chars in nearai_chat.rs error
  messages to prevent log bloat and potential data leakage
- Delegate 4 missing LlmProvider methods in FailoverProvider
  (model_metadata, seed_response_chain, get_response_chain_id,
  calculate_cost) to last-used provider instead of trait defaults

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* refactor(llm): add RetryProvider, remove openai_compatible_chat, harden decorators

- Add composable RetryProvider decorator wrapping any LlmProvider with
  exponential backoff + jitter, respecting RateLimited retry_after hints
- Remove openai_compatible_chat.rs — replaced by rig adapter + RetryProvider
- Remove internal retry loop from nearai.rs (was causing double-retry
  with external RetryProvider, up to 16 attempts instead of 4)
- Remove internal retry loop from nearai_chat.rs (same issue)
- Wire RetryProvider into main.rs composition chain: each provider gets
  its own retry wrapper before failover
- Move normalize_tool_name to rig_adapter.rs for all rig-based providers
- Reconcile is_retryable() vs is_transient() error classification:
  ModelNotAvailable no longer retryable, Json no longer transient
- Fix unchecked Duration subtraction panic in circuit_breaker.rs
- Make failover.rs use shared is_retryable() from retry.rs
- Remove stale #[allow(dead_code)] on NearAiResponse::id (field is used)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: address PR review feedback — error handling, dimension validation, libSQL warning

- Replace response.text().await.unwrap_or_default() with proper error
  propagation in nearai.rs and nearai_chat.rs (4 call sites). Failures
  now return LlmError::RequestFailed with context instead of silently
  proceeding with an empty string.
- Add embedding dimension validation in OllamaEmbeddings::embed_batch():
  returns EmbeddingError if Ollama returns embeddings with a dimension
  that doesn't match the configured value.
- Add runtime warning when libSQL backend is used with non-1536 embedding
  dimension, since the libSQL schema uses F32_BLOB(1536) and cannot store
  different-dimension vectors.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* Apply suggestions from code review

Co-authored-by: Copilot <[email protected]>

---------

Co-authored-by: panosAthDbx <[email protected]>
Co-authored-by: panosAthDBX <[email protected]>
Co-authored-by: panosAthDBX <[email protected]>
Co-authored-by: Claude Opus 4.6 <[email protected]>
Co-authored-by: Copilot <[email protected]>

src/agent/session.rs

@@ -16,7 +16,7 @@ use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 
-use crate::llm::ChatMessage;
+use crate::llm::{ChatMessage, ToolCall};
 
 /// A session containing one or more threads.
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -148,6 +148,10 @@ pub struct PendingApproval {
     pub tool_call_id: String,
     /// Context messages at the time of the request (to resume from).
     pub context_messages: Vec<ChatMessage>,
+    /// Remaining tool calls from the same assistant message that were not
+    /// executed yet when approval was requested.
+    #[serde(default)]
+    pub deferred_tool_calls: Vec<ToolCall>,
 }
 
 /// A conversation thread within a session.
@@ -946,6 +950,7 @@ mod tests {
             description: "dangerous command".to_string(),
             tool_call_id: "call_123".to_string(),
             context_messages: vec![ChatMessage::user("do it")],
+            deferred_tool_calls: vec![],
         };
 
         thread.await_approval(approval);
@@ -969,6 +974,7 @@ mod tests {
             description: "test".to_string(),
             tool_call_id: "call_456".to_string(),
             context_messages: vec![],
+            deferred_tool_calls: vec![],
         };
 
         thread.await_approval(approval);