feat: comprehensive import progress tracking for all 7 formats

Add real-time progress reporting throughout the entire import pipeline
with a standardized API that works across all supported formats.

Workshop Team Feature Request:
- Eliminates "0% complete" hangs during AI extraction
- Shows continuous progress with entities/sec, throughput, ETA
- Reports contextual messages ("Processing page 5 of 23")
- Standardized progress API for CSV, PDF, Excel, JSON, Markdown, YAML, DOCX

Core Changes:
- Add FormatHandlerProgressHooks interface for extensible progress
- Wire up all 3 binary format handlers (CSV, PDF, Excel) with 7+ progress points
- Wire up all 4 text format importers (JSON, Markdown, YAML, DOCX)
- Add ImportProgress interface with stage, message, counts, throughput, ETA
- ImportCoordinator normalizes all format progress to standard interface

CLI Improvements:
- Import command now uses brain.import() directly with full progress
- Add --include-vfs flag to find command (v4.4.0 compatibility)
- Add --confidence and --weight options to add command

Documentation:
- docs/guides/standard-import-progress.md - Universal API guide
- docs/guides/import-progress-implementation.md - Developer guide
- docs/guides/import-progress-examples.md - Practical examples
- JSDoc on brain.import() with universal handler examples

Result: ONE progress handler works for ALL 7 formats with zero format-specific code!

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

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

src/importers/SmartExcelImporter.ts

@@ -184,7 +184,43 @@ export class SmartExcelImporter {
     }
 
     // Parse Excel using existing handler
-    const processedData = await this.excelHandler.process(buffer, options)
+    // v4.5.0: Pass progress hooks to handler for file parsing progress
+    const processedData = await this.excelHandler.process(buffer, {
+      ...options,
+      totalBytes: buffer.length,
+      progressHooks: {
+        onBytesProcessed: (bytes) => {
+          // Handler reports bytes processed during parsing
+          opts.onProgress?.({
+            processed: 0,
+            total: 0,
+            entities: 0,
+            relationships: 0,
+            phase: `Parsing Excel (${Math.round((bytes / buffer.length) * 100)}%)`
+          })
+        },
+        onCurrentItem: (message) => {
+          // Handler reports current processing step (e.g., "Reading sheet: Sales (1/3)")
+          opts.onProgress?.({
+            processed: 0,
+            total: 0,
+            entities: 0,
+            relationships: 0,
+            phase: message
+          })
+        },
+        onDataExtracted: (count, total) => {
+          // Handler reports rows extracted
+          opts.onProgress?.({
+            processed: 0,
+            total: total || count,
+            entities: 0,
+            relationships: 0,
+            phase: `Extracted ${count} rows from Excel`
+          })
+        }
+      }
+    })
     const rows = processedData.data
 
     if (rows.length === 0) {