graph health: fix-categories, cap-degree, link-orphans

Three new tools for structural graph health:

- fix-categories: rule-based recategorization fixing core inflation
  (225 → 26 core nodes). Only identity.md and kent.md stay core;
  everything else reclassified to tech/obs/gen by file prefix rules.

- cap-degree: two-phase degree capping. First prunes weakest Auto
  edges, then prunes Link edges to high-degree targets (they have
  alternative paths). Brought max degree from 919 → 50.

- link-orphans: connects degree-0/1 nodes to most textually similar
  connected nodes via cosine similarity. Linked 614 orphans.

Also: community detection now filters edges below strength 0.3,
preventing weak auto-links from merging unrelated communities.

Pipeline updated: consolidate-full now runs link-orphans + cap-degree
instead of triangle-close (which was counterproductive — densified
hub neighborhoods instead of building bridges).

Net effect: Gini 0.754 → 0.546, max degree 919 → 50.

src/digest.rs

@@ -922,6 +922,27 @@ pub fn consolidate_full(store: &mut Store) -> Result<(), String> {
         }
     }
 
+    // --- Step 3b: Link orphans ---
+    log.write("\n--- Step 3b: Link orphans ---")?;
+    println!("\n--- Linking orphan nodes ---");
+    *store = Store::load()?;
+
+    let (lo_orphans, lo_added) = neuro::link_orphans(store, 2, 3, 0.15);
+    log.write(&format!("  {} orphans, {} links added", lo_orphans, lo_added))?;
+
+    // --- Step 3c: Cap degree ---
+    log.write("\n--- Step 3c: Cap degree ---")?;
+    println!("\n--- Capping node degree ---");
+    *store = Store::load()?;
+
+    match store.cap_degree(50) {
+        Ok((hubs, pruned)) => {
+            store.save()?;
+            log.write(&format!("  {} hubs capped, {} edges pruned", hubs, pruned))?;
+        }
+        Err(e) => log.write(&format!("  ERROR: {}", e))?,
+    }
+
     // --- Step 4: Digest auto ---
     log.write("\n--- Step 4: Digest auto ---")?;
     println!("\n--- Generating missing digests ---");