Add global installation capability and fix venv accessibility issue

- Add make install-global target with intelligent installation methods
- Support pipx (recommended), pip --user, and fallback options
- Resolve issue where kaizen-agentic was only available in local venv
- Update documentation to clearly explain 4 installation options:
  - Development mode (local venv)
  - Global installation (any directory)
  - Local package testing (local venv)
  - Future PyPI installation
- CLI now available globally from any directory after make install-global

Fixes the core issue where users couldn't access kaizen-agentic from other repos.

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

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

docs/GETTING_STARTED.md

@@ -8,7 +8,7 @@ This guide walks you through using Kaizen Agentic agents in any project, from in
 
 ### 1. Install the Package
 
-**Option A: From Source (Current - Development Version)**
+**Option A: From Source (Development Mode)**
 
 ```bash
 # Clone the repository
@@ -18,14 +18,14 @@ cd kaizen-agentic
 # Set up development environment
 make setup-complete
 
-# Install CLI tool
+# Install CLI tool (local to project)
 make agents-install-cli
 
-# Activate virtual environment
+# Activate virtual environment (required for each session)
 source .venv/bin/activate
 ```
 
-**Option B: From Local Package (Test PyPI Installation)**
+**Option B: Local Package Testing (PyPI-equivalent)**
 
 ```bash
 # Clone the repository and build package
@@ -33,22 +33,40 @@ git clone https://github.com/kaizen-agentic/kaizen-agentic.git
 cd kaizen-agentic
 make setup-complete
 
-# Build and install from local package
+# Build and install from local package (local to project)
 python3 -m build
 make install-local
 
-# Activate virtual environment
+# Activate virtual environment (required for each session)
 source .venv/bin/activate
 ```
 
-**Option C: From PyPI (Coming Soon)**
+**Option C: Global Installation (Available from any directory)**
+
+```bash
+# Clone the repository and build package
+git clone https://github.com/kaizen-agentic/kaizen-agentic.git
+cd kaizen-agentic
+make setup-complete
+
+# Build and install globally
+python3 -m build
+make install-global
+
+# No virtual environment activation needed
+# CLI available from any directory
+```
+
+**Option D: From PyPI (Coming Soon)**
 
 ```bash
 # Will be available once v1.0.0 is published
 pip install kaizen-agentic
+# or
+pipx install kaizen-agentic  # Recommended for global CLI tools
 ```
 
-> **📦 Release Status**: v1.0.0 is ready for publication. Test local installation with `make install-local` before PyPI publication.
+> **📦 Release Status**: v1.0.0 is ready for publication. Use `make install-global` for system-wide availability.
 
 ### 2. Verify Installation