feat: complete VFS with Knowledge Layer integration

- Add importFile() method for single file imports
- Implement entity helper methods (linkEntities, findEntityOccurrences)
- Fix critical embedding tokenizer bug (char.charCodeAt error)
- Fix removeRelationship to actually remove using brain.unrelate()
- Add setMetadata/getMetadata methods
- Fix GitBridge to query real relationships and events
- Enable background Knowledge Layer processing
- Rewrite README to emphasize knowledge over files
- Add comprehensive VFS documentation (core, knowledge layer, examples)
- Add complete test suite covering all VFS methods

This completes the VFS implementation with full Knowledge Layer support,
enabling files as living knowledge that understand themselves, evolve
over time, and connect to everything related.

src/brainy.ts

@@ -1819,9 +1819,61 @@ export class Brainy<T = any> implements BrainyInterface<T> {
 
   /**
    * Embed data into vector
+   * Handles any data type by converting to string representation
    */
   async embed(data: any): Promise<Vector> {
-    return this.embedder(data)
+    // Handle different data types intelligently
+    let textToEmbed: string | string[]
+
+    if (typeof data === 'string') {
+      textToEmbed = data
+    } else if (Array.isArray(data)) {
+      // Array of items - convert each to string
+      textToEmbed = data.map(item => {
+        if (typeof item === 'string') return item
+        if (typeof item === 'number' || typeof item === 'boolean') return String(item)
+        if (item && typeof item === 'object') {
+          // For objects, try to extract meaningful text
+          if (item.data) return String(item.data)
+          if (item.content) return String(item.content)
+          if (item.text) return String(item.text)
+          if (item.name) return String(item.name)
+          if (item.title) return String(item.title)
+          if (item.description) return String(item.description)
+          // Fallback to JSON for complex objects
+          try {
+            return JSON.stringify(item)
+          } catch {
+            return String(item)
+          }
+        }
+        return String(item)
+      })
+    } else if (data && typeof data === 'object') {
+      // Single object - extract meaningful text
+      if (data.data) textToEmbed = String(data.data)
+      else if (data.content) textToEmbed = String(data.content)
+      else if (data.text) textToEmbed = String(data.text)
+      else if (data.name) textToEmbed = String(data.name)
+      else if (data.title) textToEmbed = String(data.title)
+      else if (data.description) textToEmbed = String(data.description)
+      else {
+        // For complex objects, create a descriptive string
+        try {
+          textToEmbed = JSON.stringify(data)
+        } catch {
+          textToEmbed = String(data)
+        }
+      }
+    } else if (data === null || data === undefined) {
+      // Handle null/undefined gracefully
+      textToEmbed = ''
+    } else {
+      // Numbers, booleans, etc - convert to string
+      textToEmbed = String(data)
+    }
+
+    return this.embedder(textToEmbed)
   }
 
   /**