feat: add CLI support for pipeline visualization

Add `gitlab-ci-builder visualize` command to generate Mermaid diagrams,
ASCII trees, and stage tables directly from the terminal. Supports private
repositories and self-hosted GitLab instances.

Author: noxify

.changeset/add-cli-visualize.md

@@ -0,0 +1,50 @@
+---
+"@noxify/gitlab-ci-builder": minor
+---
+
+Add CLI visualization tool for GitLab CI pipelines
+
+- New `gitlab-ci-builder` command-line tool with `visualize` subcommand
+- Supports multiple input formats: local YAML files, remote URLs, and TypeScript config files
+- Three visualization formats:
+  - Mermaid diagram: Interactive flowchart visualization
+  - ASCII tree: Text-based dependency tree
+  - Stage table: Organized view by pipeline stages
+- Built-in support for extends resolution and dependency analysis
+- Easy to use: `npx @noxify/gitlab-ci-builder visualize .gitlab-ci.yml`
+
+**CLI Usage:**
+
+```bash
+# Visualize local YAML file (all formats)
+gitlab-ci-builder visualize .gitlab-ci.yml
+
+# Show only Mermaid diagram
+gitlab-ci-builder visualize .gitlab-ci.yml -f mermaid
+
+# Visualize remote pipeline
+gitlab-ci-builder visualize https://gitlab.com/my-org/my-project/-/raw/main/.gitlab-ci.yml
+
+# Show ASCII tree without stages
+gitlab-ci-builder visualize pipeline.yml -f ascii --show-stages=false
+```
+
+**Programmatic Usage:**
+
+```typescript
+import { visualizeYaml } from "@noxify/gitlab-ci-builder"
+
+const yamlContent = `
+stages: [build, test]
+build:
+  stage: build
+  script: npm run build
+`
+
+const result = await visualizeYaml(yamlContent, { format: "all" })
+console.log(result.mermaid) // Mermaid diagram
+console.log(result.ascii) // ASCII tree
+console.log(result.table) // Stage table
+```
+
+The CLI tool provides a quick way to understand complex pipeline configurations and visualize job dependencies without needing to write code. The subcommand structure allows for future expansion with additional commands. Future enhancements will include support for resolving external includes (local, remote, project, and template includes).