Implement tool approval, fix tool definition refresh, and wire embeddings

This commit addresses three critical issues from code review:

1. Tool approval enforcement: Tools declaring requires_approval() (shell,
   http, file write/patch, build_software) now gate execution. Adds
   PendingApproval struct, session-scoped auto-approved tools set, and
   approval flow with yes/no/always commands.

2. Tool definition refresh: Tool definitions now refresh each iteration
   in both chat and job loops, so newly built tools become visible
   immediately within the same session.

3. Worker tool call handling: Changed respond() to respond_with_tools()
   when select_tools returns empty, properly executing tool calls instead
   of formatting them as text.

Also includes prior work from the plan:
- Wire embeddings provider (OpenAI + NEAR AI) to workspace
- Load workspace system prompt (identity files) into LLM context
- Route heartbeat notifications through channel manager
- Enable auto-context compaction when threshold exceeded
- Refactor to config structs (AgentDeps, WorkerDeps, LlmCallRecord)
- Fix clippy warnings (saturating_sub, too_many_arguments)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

src/history/mod.rs

@@ -9,4 +9,4 @@ mod analytics;
 mod store;
 
 pub use analytics::{JobStats, ToolStats};
-pub use store::Store;
+pub use store::{LlmCallRecord, Store};

src/history/store.rs

@@ -9,6 +9,19 @@ use crate::config::DatabaseConfig;
 use crate::context::{ActionRecord, JobContext, JobState};
 use crate::error::DatabaseError;
 
+/// Record for an LLM call to be persisted.
+#[derive(Debug, Clone)]
+pub struct LlmCallRecord<'a> {
+    pub job_id: Option<Uuid>,
+    pub conversation_id: Option<Uuid>,
+    pub provider: &'a str,
+    pub model: &'a str,
+    pub input_tokens: u32,
+    pub output_tokens: u32,
+    pub cost: Decimal,
+    pub purpose: Option<&'a str>,
+}
+
 /// Database store for the agent.
 pub struct Store {
     pool: Pool,
@@ -335,17 +348,7 @@ impl Store {
     // ==================== LLM Calls ====================
 
     /// Record an LLM call.
-    pub async fn record_llm_call(
-        &self,
-        job_id: Option<Uuid>,
-        conversation_id: Option<Uuid>,
-        provider: &str,
-        model: &str,
-        input_tokens: u32,
-        output_tokens: u32,
-        cost: Decimal,
-        purpose: Option<&str>,
-    ) -> Result<Uuid, DatabaseError> {
+    pub async fn record_llm_call(&self, record: &LlmCallRecord<'_>) -> Result<Uuid, DatabaseError> {
         let conn = self.conn().await?;
         let id = Uuid::new_v4();
 
@@ -356,14 +359,14 @@ impl Store {
             "#,
             &[
                 &id,
-                &job_id,
-                &conversation_id,
-                &provider,
-                &model,
-                &(input_tokens as i32),
-                &(output_tokens as i32),
-                &cost,
-                &purpose,
+                &record.job_id,
+                &record.conversation_id,
+                &record.provider,
+                &record.model,
+                &(record.input_tokens as i32),
+                &(record.output_tokens as i32),
+                &record.cost,
+                &record.purpose,
             ],
         )
         .await?;