feat: wire tools into LocalBackend turn loop

- Added max_tool_rounds (configurable per-agent) to LlmConfig
- Rewrote run_turn() with multi-round tool-calling loop
  (max 10 rounds by default, 0 disables tools)
- Converts core ToolDefinitions → bifrost ToolDefinitions
- Streams tool execution status to TUI via BackendEvent::Token
- Continues consciousness processing (surfacing, reflection, archivist)
  after tool loop completes
- Fixed git2::Config Send issue in memory/mod.rs (scoped block)

Closes: docs/tasks/tool-wiring.md

src/core/memory/mod.rs

@@ -160,10 +160,12 @@ impl MemoryRepo {
         let repo = git2::Repository::init(mem_path)
             .context("initializing git repository for memory")?;
 
-        // Set user config for commits
-        let mut config = repo.config().context("opening repo config")?;
-        config.set_str("user.name", &self.agent_id)?;
-        config.set_str("user.email", &format!("{}@souveraine.local", self.agent_id))?;
+        // Set user config for commits (scoped to drop before .await)
+        {
+            let mut config = repo.config().context("opening repo config")?;
+            config.set_str("user.name", &self.agent_id)?;
+            config.set_str("user.email", &format!("{}@souveraine.local", self.agent_id))?;
+        }
 
         // Write initial placeholder files with frontmatter
         let persona_content = render_frontmatter(