refactor: organize scripts/, remove stale root dirs, clean up structure

scripts/ reorganization:
- Sort 14 loose root scripts into subfolders:
  blockchain/ (genesis, proposer, mock chain, testnet BTC)
  dev/ (CLI wrapper, dev services, OpenAPI gen, systemd setup, domain proxy)
  ops/ (coordinator proxy, remote tunnel)
  gpu/ (miner workflow)
- Merge scripts/testing/ into scripts/test/ (eliminate duplicate folder)
- Create scripts/examples/ for usage demos and simulations

Root-level cleanup:
- Move home/ (12 simulation scripts) → scripts/examples/
- Move dev-utils/ (2 files) → scripts/dev/
- Move protocols/receipts/sample → tests/fixtures/
- Delete stale src/ (duplicate of apps/blockchain-node/src/)
- Remove empty home/, dev-utils/, protocols/ directories

Documentation updates:
- Update docs/6_architecture/8_codebase-structure.md tree and table
- Update root README.md tree to reflect new structure

scripts/examples/simulate.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+"""
+Complete simulation: Client pays for GPU services, Miner earns AITBC
+"""
+
+import os
+import sys
+import time
+import subprocess
+
+def run_wallet_command(wallet_type, command, description):
+    """Run a wallet command and display results"""
+    print(f"\n{'='*60}")
+    print(f"💼 {wallet_type}: {description}")
+    print(f"{'='*60}")
+    
+    wallet_dir = os.path.join(os.path.dirname(__file__), wallet_type.lower())
+    cmd = f"cd {wallet_dir} && python3 wallet.py {command}"
+    
+    result = subprocess.run(cmd, shell=True, capture_output=True, text=True)
+    print(result.stdout)
+    
+    if result.stderr:
+        print(f"Error: {result.stderr}")
+    
+    return result
+
+def main():
+    print("🎭 AITBC Local Simulation")
+    print("=" * 60)
+    print("Simulating client and GPU provider interactions")
+    print()
+    
+    # Step 1: Initialize wallets with genesis distribution
+    print("📋 STEP 1: Initialize Wallets")
+    os.system("cd /home/oib/windsurf/aitbc/home && python3 genesis.py")
+    
+    input("\nPress Enter to continue...")
+    
+    # Step 2: Check initial balances
+    print("\n📋 STEP 2: Check Initial Balances")
+    run_wallet_command("Client", "balance", "Initial client balance")
+    run_wallet_command("Miner", "balance", "Initial miner balance")
+    
+    input("\nPress Enter to continue...")
+    
+    # Step 3: Client submits a job (using CLI tool)
+    print("\n📋 STEP 3: Client Submits Job")
+    print("-" * 40)
+    
+    # Submit job to coordinator
+    result = subprocess.run(
+        "cd /home/oib/windsurf/aitbc/cli && python3 client.py submit inference --model llama-2-7b --prompt 'What is the future of AI?'",
+        shell=True,
+        capture_output=True,
+        text=True
+    )
+    
+    print(result.stdout)
+    
+    # Extract job ID if successful
+    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
+    
+    input("\nPress Enter to continue...")
+    
+    # Step 4: Miner processes the job
+    print("\n📋 STEP 4: Miner Processes Job")
+    print("-" * 40)
+    
+    if job_id:
+        print(f"⛏️  Miner found job: {job_id}")
+        print("⚙️  Processing job...")
+        time.sleep(2)
+        
+        # Miner earns AITBC for completing the job
+        run_wallet_command(
+            "Miner", 
+            f"earn 50.0 --job {job_id} --desc 'Inference task completed'", 
+            "Miner earns AITBC"
+        )
+    
+    input("\nPress Enter to continue...")
+    
+    # Step 5: Client pays for the service
+    print("\n📋 STEP 5: Client Pays for Service")
+    print("-" * 40)
+    
+    if job_id:
+        # Get miner address
+        miner_result = subprocess.run(
+            "cd /home/oib/windsurf/aitbc/home/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:
+            run_wallet_command(
+                "Client",
+                f"send 50.0 {miner_address} 'Payment for inference job {job_id}'",
+                "Client pays for completed job"
+            )
+    
+    input("\nPress Enter to continue...")
+    
+    # Step 6: Check final balances
+    print("\n📋 STEP 6: Final Balances")
+    run_wallet_command("Client", "balance", "Final client balance")
+    run_wallet_command("Miner", "balance", "Final miner balance")
+    
+    print("\n🎉 Simulation Complete!")
+    print("=" * 60)
+    print("Summary:")
+    print("  • Client submitted job and paid 50 AITBC")
+    print("  • Miner processed job and earned 50 AITBC")
+    print("  • Transaction recorded on blockchain")
+    print()
+    print("💡 You can:")
+    print("  • Run 'cd home/client && python3 wallet.py history' to see client transactions")
+    print("  • Run 'cd home/miner && python3 wallet.py stats' to see miner earnings")
+    print("  • Submit more jobs with the CLI tools")
+
+if __name__ == "__main__":
+    main()