feat: implement intelligent scan command with ast-grep integration

- Add comprehensive project scanning with 4-phase analysis
- Integrate @ast-grep/cli for advanced syntax tree analysis
- Support AI-powered project understanding with fallback
- Generate structured JSON output with file/directory summaries
- Add configurable include/exclude patterns and scan depth
- Provide transparent logging for each analysis phase
- Create task-master scan command with full CLI options

This addresses issue #78 by enabling quick project structure analysis
for easier Task Master adoption on existing projects.

Co-authored-by: Ralph Khreish <Crunchyman-ralph@users.noreply.github.com>

.changeset/intelligent-scan-command.md

@@ -0,0 +1,23 @@
+---
+"task-master-ai": minor
+---
+
+Add intelligent `scan` command for automated codebase analysis
+
+Introduces a comprehensive project scanning feature that intelligently analyzes codebases using ast-grep and AI-powered analysis. The new `task-master scan` command provides:
+
+- **Multi-phase Analysis**: Performs iterative scanning (project type identification → entry points → core structure → recursive deepening)
+- **AST-grep Integration**: Uses ast-grep as an AI SDK tool for advanced code structure analysis
+- **AI Enhancement**: Optional AI-powered analysis for intelligent project understanding
+- **Structured Output**: Generates detailed JSON reports with file/directory summaries
+- **Transparent Logging**: Clear progress indicators showing each analysis phase
+- **Configurable Options**: Supports custom include/exclude patterns, scan depth, and output paths
+
+This feature addresses the challenge of quickly understanding existing project structures when adopting Task Master, significantly streamlining initial setup and project onboarding.
+
+Usage:
+```bash
+task-master scan --output=project_scan.json
+task-master scan --include="*.js,*.ts" --exclude="*.test.*" --depth=3
+task-master scan --no-ai  # Skip AI analysis for faster results
+```