Native memory tools + MCP server + distill agent improvements

Tools:
- Add native memory_render, memory_write, memory_search,
  memory_links, memory_link_set, memory_link_add, memory_used
  tools to poc-agent (tools/memory.rs)
- Add MCP server (~/bin/memory-mcp.py) exposing same tools
  for Claude Code sessions
- Wire memory tools into poc-agent dispatch and definitions
- poc-memory daemon agents now use memory_* tools instead of
  bash poc-memory commands — no shell quoting issues

Distill agent:
- Rewrite distill.agent prompt: "agent of PoC's subconscious"
  framing, focus on synthesis and creativity over bookkeeping
- Add {{neighborhood}} placeholder: full seed node content +
  all neighbors with content + cross-links between neighbors
- Remove content truncation in prompt builder — agents need
  full content for quality work
- Remove bag-of-words similarity suggestions — agents have
  tools, let them explore the graph themselves
- Add api_reasoning config option (default: "high")
- link-set now deduplicates — collapses duplicate links
- Full tool call args in debug logs (was truncated to 80 chars)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poc-memory/src/config.rs

@@ -61,6 +61,8 @@ pub struct Config {
     pub api_key: Option<String>,
     /// Model name to use with the direct API endpoint.
     pub api_model: Option<String>,
+    /// Reasoning effort for API calls ("none", "low", "medium", "high").
+    pub api_reasoning: String,
 }
 
 impl Default for Config {
@@ -93,6 +95,7 @@ impl Default for Config {
             api_base_url: None,
             api_key: None,
             api_model: None,
+            api_reasoning: "high".to_string(),
         }
     }
 }
@@ -180,6 +183,10 @@ impl Config {
             }
         }
 
+        if let Some(s) = mem.get("api_reasoning").and_then(|v| v.as_str()) {
+            config.api_reasoning = s.to_string();
+        }
+
         // Resolve API settings from the shared model/backend config.
         // memory.agent_model references a named model; we look up its
         // backend to get base_url and api_key.