feat: add neural extraction APIs with NounType taxonomy

Add brain.extract() and brain.extractConcepts() methods that use
NeuralEntityExtractor with embeddings and sophisticated NounType
taxonomy (30+ entity types) for semantic entity and concept extraction.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/vfs/semantic/projections/TemporalProjection.ts

@@ -0,0 +1,103 @@
+/**
+ * Temporal Projection Strategy
+ *
+ * Maps time-based paths to files modified at that time
+ * Uses EXISTING MetadataIndexManager with range queries
+ */
+
+import { Brainy } from '../../../brainy.js'
+import { VirtualFileSystem } from '../../VirtualFileSystem.js'
+import { FindParams } from '../../../types/brainy.types.js'
+import { BaseProjectionStrategy } from '../ProjectionStrategy.js'
+import { VFSEntity } from '../../types.js'
+
+/**
+ * Temporal Projection: /as-of/<YYYY-MM-DD>/<subpath>
+ *
+ * Uses EXISTING infrastructure:
+ * - Brainy.find() with range queries (REAL)
+ * - MetadataIndexManager.$gte/$lte operators (REAL)
+ * - VFSMetadata.modified field (REAL - types.ts line 49)
+ */
+export class TemporalProjection extends BaseProjectionStrategy {
+  readonly name = 'time'
+
+  /**
+   * Convert date to Brainy FindParams with range query
+   */
+  toQuery(date: Date, subpath?: string): FindParams {
+    // Get start and end of day (24-hour window)
+    const startOfDay = new Date(date)
+    startOfDay.setHours(0, 0, 0, 0)
+
+    const endOfDay = new Date(date)
+    endOfDay.setHours(23, 59, 59, 999)
+
+    const query: FindParams = {
+      where: {
+        vfsType: 'file',
+        modified: {
+          greaterEqual: startOfDay.getTime(),  // BFO operator
+          lessEqual: endOfDay.getTime()        // BFO operator
+        }
+      },
+      limit: 1000
+    }
+
+    // Filter by filename if subpath specified
+    if (subpath) {
+      query.where = {
+        ...query.where,
+        anyOf: [  // BFO logical operator (not $or)
+          { name: subpath },
+          { path: { endsWith: subpath } }  // BFO operator (not $regex)
+        ]
+      }
+    }
+
+    return query
+  }
+
+  /**
+   * Resolve date to entity IDs using REAL Brainy.find()
+   * Uses MetadataIndexManager range queries for O(log n) performance
+   */
+  async resolve(brain: Brainy, vfs: VirtualFileSystem, date: Date): Promise<string[]> {
+    const startOfDay = new Date(date)
+    startOfDay.setHours(0, 0, 0, 0)
+
+    const endOfDay = new Date(date)
+    endOfDay.setHours(23, 59, 59, 999)
+
+    // Use REAL Brainy metadata filtering with range operators
+    const results = await brain.find({
+      where: {
+        vfsType: 'file',
+        modified: {
+          greaterEqual: startOfDay.getTime(),  // BFO operator
+          lessEqual: endOfDay.getTime()        // BFO operator
+        }
+      },
+      limit: 1000
+    })
+
+    return this.extractIds(results)
+  }
+
+  /**
+   * List recently modified files
+   */
+  async list(brain: Brainy, vfs: VirtualFileSystem, limit = 100): Promise<VFSEntity[]> {
+    const oneDayAgo = Date.now() - (24 * 60 * 60 * 1000)
+
+    const results = await brain.find({
+      where: {
+        vfsType: 'file',
+        modified: { greaterEqual: oneDayAgo }  // BFO operator
+      },
+      limit
+    })
+
+    return results.map(r => r.entity as VFSEntity)
+  }
+}