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.

src/integrations/sheets/GoogleSheetsIntegration.ts

@@ -15,7 +15,6 @@
 
 import { IntegrationBase, HTTPIntegration } from '../core/IntegrationBase.js'
 import { IntegrationConfig } from '../core/types.js'
-import { AugmentationManifest } from '../../augmentations/manifest.js'
 import { Entity, FindParams } from '../../types/brainy.types.js'
 import { NounType, VerbType } from '../../types/graphTypes.js'
 
@@ -92,10 +91,11 @@ interface SheetsResponse {
  *
  * @example
  * ```typescript
- * brain.augmentations.register(new GoogleSheetsIntegration({
+ * const sheets = new GoogleSheetsIntegration({
  *   basePath: '/sheets',
  *   maxResults: 1000
- * }))
+ * })
+ * await sheets.initialize()
  * ```
  */
 export class GoogleSheetsIntegration
@@ -283,7 +283,7 @@ export class GoogleSheetsIntegration
   /**
    * Get manifest
    */
-  getManifest(): AugmentationManifest {
+  getManifest(): Record<string, any> {
     return {
       id: 'sheets',
       name: 'Google Sheets Integration',