Issue 27: SDK Demo Application

[laraibg786]

Goal

Build a simple Python CLI demo application that showcases SDK initialization, license activation, heartbeat loop, and state callbacks. Customers use this as a reference for integration.

Requirements

Functional

• Prompt for vendor API key and license key on startup.
• Auto-generate device fingerprint if not provided.
• Activate license via SDK and display session info.
• Start heartbeat loop with 1-minute interval (for demo speed).
• Print state transitions and remaining grace time on each heartbeat.
• Support pause (p) / resume (r) to simulate offline behavior.
• Gracefully stop on Ctrl+C.

Technical

• Location: demo/demo.py.
• Dependencies: permit_sdk (Issue 23: Python SDK Core Client #23, Issue 24: SDK Heartbeat Loop and State Machine #24).
• Well-commented: Code serves as integration reference.

Acceptance Criteria

• Demo runs end-to-end: activate → heartbeat → grace → expire.
• Offline simulation (pause/resume) demonstrates grace behavior.
• Code is well-commented and readable as a reference implementation.

Dependencies

• Blocked by: Issue 23: Python SDK Core Client #23, Issue 24: SDK Heartbeat Loop and State Machine #24, Issue 25: SDK Test Suite #25.
• Blocks: Nothing.