agents: tool-enabled LLM calls + DELETE action support

Add call_for_def() that threads model and tools from agent definitions
through to claude CLI. Tool-enabled agents get --allowedTools instead
of --tools "" and a longer 15-minute timeout for multi-turn work.

Add ActionKind::Delete with parse/apply support so agents can delete
nodes (used by organize agent for deduplication).

Use call_for_def() in run_one_agent instead of hardcoded call_sonnet.

poc-memory/src/agents/consolidate.rs

@@ -233,6 +233,8 @@ pub fn apply_consolidation(store: &mut Store, do_apply: bool, report_key: Option
                     println!("  REFINE {}", key),
                 knowledge::ActionKind::Demote { key } =>
                     println!("  DEMOTE {}", key),
+                knowledge::ActionKind::Delete { key } =>
+                    println!("  DELETE {}", key),
             }
         }
         println!("\nTo apply: poc-memory apply-consolidation --apply");