feat(core): add ollama lifecycle management for cron sync

Add src/core/ollama_mgmt.rs module that handles Ollama detection, startup,
and health checking. This enables cron-based sync to automatically start
Ollama when it's installed but not running, ensuring embeddings are always
available during unattended sync runs.

Integration points:
- sync handler (--lock mode): calls ensure_ollama() before embedding phase
- cron status: displays Ollama health (installed/running/not-installed)
- robot JSON: includes OllamaStatusBrief in cron status response

The module handles local vs remote Ollama URLs, IPv6, process detection
via lsof, and graceful startup with configurable wait timeouts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/handlers.rs

@@ -1664,6 +1664,24 @@ async fn handle_sync_cmd(
         None
     };
 
+    // In cron mode (--lock), ensure Ollama is running for embeddings
+    if args.lock {
+        let result = lore::core::ollama_mgmt::ensure_ollama(&config.embedding.base_url);
+        if !result.installed {
+            tracing::warn!(
+                "Ollama is not installed — embeddings will be skipped. {}",
+                result.install_hint.as_deref().unwrap_or("")
+            );
+        } else if result.started {
+            tracing::info!("Started ollama serve (was not running)");
+        } else if !result.running {
+            tracing::warn!(
+                "Failed to start Ollama: {}",
+                result.error.as_deref().unwrap_or("unknown error")
+            );
+        }
+    }
+
     // Surgical mode: run_sync_surgical manages its own recorder, signal, and recording.
     // Skip the normal recorder setup and let the dispatch handle everything.
     if options.is_surgical() {