chore(systemd): remove obsolete systemd service files and update infrastructure documentation

- Remove 8 unused systemd service files from coordinator-api/systemd/
  - aitbc-adaptive-learning.service (port 8005)
  - aitbc-advanced-ai.service
  - aitbc-enterprise-api.service
  - aitbc-gpu-multimodal.service (port 8003)
  - aitbc-marketplace-enhanced.service (port 8006)
  - aitbc-modality-optimization.service (port 8004)
  - aitbc-multimodal.service (port 8002)
  - aitbc-openclaw-enhanced.service (port 8007

dev/examples/simple_job_flow.py

@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+"""
+Simple job flow: Client -> GPU Provider -> Payment
+"""
+
+import subprocess
+import time
+
+def main():
+    print("📋 AITBC Job Flow: Client -> GPU Provider -> Payment")
+    print("=" * 60)
+    
+    print("\n📝 STEP 1: Client submits job 'hello'")
+    print("-" * 40)
+    
+    # Submit job
+    result = subprocess.run(
+        'cd ../cli && python3 client.py demo',
+        shell=True,
+        capture_output=True,
+        text=True
+    )
+    print(result.stdout)
+    
+    # Extract job ID
+    job_id = None
+    if "Job ID:" in result.stdout:
+        for line in result.stdout.split('\n'):
+            if "Job ID:" in line:
+                job_id = line.split()[-1]
+                break
+    
+    if not job_id:
+        print("❌ Failed to submit job")
+        return
+    
+    print(f"\n📮 Job submitted: {job_id}")
+    
+    print("\n⛏️  STEP 2: GPU Provider processes job")
+    print("-" * 40)
+    print("   (Start miner with: python3 cli/miner.py mine)")
+    print("   The miner will automatically pick up the job")
+    
+    # Simulate miner processing
+    print("\n   💭 Simulating job processing...")
+    time.sleep(2)
+    
+    # Miner earns AITBC
+    print("   ✅ Job processed!")
+    print("   💰 Miner earned 25 AITBC")
+    
+    # Add to miner wallet
+    subprocess.run(
+        f'cd miner && python3 wallet.py earn 25.0 --job {job_id} --desc "Processed hello job"',
+        shell=True,
+        capture_output=True,
+        text=True
+    )
+    
+    print("\n💸 STEP 3: Client pays for service")
+    print("-" * 40)
+    
+    # Get miner address
+    miner_result = subprocess.run(
+        'cd miner && python3 wallet.py address',
+        shell=True,
+        capture_output=True,
+        text=True
+    )
+    
+    miner_address = None
+    if "Miner Address:" in miner_result.stdout:
+        for line in miner_result.stdout.split('\n'):
+            if "Miner Address:" in line:
+                miner_address = line.split()[-1]
+                break
+    
+    if miner_address:
+        # Client pays
+        subprocess.run(
+            f'cd client && python3 wallet.py send 25.0 {miner_address} "Payment for job {job_id}"',
+            shell=True,
+            capture_output=True,
+            text=True
+        )
+    
+    print("\n📊 STEP 4: Final balances")
+    print("-" * 40)
+    
+    print("\n   Client Wallet:")
+    subprocess.run('cd client && python3 wallet.py balance', shell=True)
+    
+    print("\n   Miner Wallet:")
+    subprocess.run('cd miner && python3 wallet.py balance', shell=True)
+    
+    print("\n✅ Complete workflow demonstrated!")
+    print("\n💡 To run with real GPU processing:")
+    print("   1. Start miner: python3 cli/miner.py mine")
+    print("   2. Submit job: python3 cli/client.py submit inference --prompt 'hello'")
+    print("   3. Check status: python3 cli/client.py status <job_id>")
+    print("   4. Pay manually: cd home/client && python3 wallet.py send <amount> <miner_address>")
+
+if __name__ == "__main__":
+    main()