refactor: remove augmentation system and semantic type matching

Remove the entire augmentation pipeline infrastructure (52 files,
~15,000 lines) and the semantic type matching system. These were
unused middleware layers adding complexity without value.

What was removed:
- src/augmentations/ directory (all augmentation implementations)
- src/augmentationManager.ts (pipeline orchestrator)
- src/types/augmentations.ts, src/types/pipelineTypes.ts
- src/shared/default-augmentations.ts
- Semantic type suggestion (BrainyTypes.suggestNoun/suggestVerb)
- src/utils/typeMatching/ (embedding-based type matcher)

What was preserved by relocating:
- Import handlers (CSV, PDF, Excel) -> src/importers/handlers/
- NeuralImportAugmentation -> src/cortex/neuralImportAugmentation.ts
- Type matching utilities -> heuristic inference in consumers

What was simplified:
- brainy.ts: operations call storage directly (no execute() wrapper)
- IntegrationBase: standalone class (no BaseAugmentation parent)
- BrainyTypes: validation-only (nouns, verbs, isValid*, get*)
- Pipeline: direct execution (no augmentation interception)
- index.ts: removed TypeSuggestion, suggestType exports
- package.json: removed stale types/augmentations export

Build passes, 1176 tests pass, 0 failures.

tests/unit/brainy/add.test.ts

@@ -482,24 +482,6 @@ describe('Brainy.add()', () => {
     })
   })
   
-  describe('augmentations', () => {
-    it('should apply augmentations during add', async () => {
-      // This would test augmentation pipeline if configured
-      // For now, just verify the entity is added correctly
-      const params = createAddParams({
-        data: 'Augmentation test',
-        type: 'thing',
-        metadata: { augment: true }
-      })
-      
-      const id = await brain.add(params)
-      const entity = await brain.get(id)
-      
-      expect(entity).not.toBeNull()
-      expect(entity!.metadata.augment).toBe(true)
-    })
-  })
-  
   describe('caching behavior', () => {
     it('should retrieve consistent entities', async () => {
       // Arrange (v5.1.0: use valid UUID format)