SIMD-0432 landed this week, enabling developers to reclaim lamports and storage from closed programs on Loader V3—eliminating a long-standing source of permanent rent lock on Solana.

```bash
# =============================================================
# SIMD-0432 in Practice: Closing a Program & Reclaiming Lamports
# =============================================================
# Tested against Solana CLI tooling on a local validator.
# Once SIMD-0432 is active on your target cluster, the
# `solana program close` command will fully reclaim lamports
# from closed Loader V3 program accounts.
#
# Prerequisites:
#   - Solana CLI >= version supporting SIMD-0432 runtime
#   - A deployed upgradeable program you want to sunset
#   - The program's upgrade authority keypair

# Step 0: Spin up a local validator (if testing locally)
# The --clone flag is optional; we just need the runtime
# feature gate for SIMD-0432 active.
solana-test-validator --reset

# Step 1: Deploy a simple program so we have something to close
# Replace with your own .so if desired
solana program deploy ./target/deploy/my_program.so \
  --keypair ~/.config/solana/id.json
# Output: Program Id: <PROGRAM_ID>

# Step 2: Verify the program account exists and note its lamport balance
solana account <PROGRAM_ID>
# Look for the lamport balance — this is the rent-exempt reserve
# that was previously unrecoverable after close.

# Step 3: Check your wallet balance before reclamation
solana balance
# e.g., 496.123 SOL

# Step 4: Close the program and reclaim lamports
# The --recipient flag specifies where reclaimed lamports go.
# Defaults to the fee payer if omitted.
solana program close <PROGRAM_ID> \
  --keypair ~/.config/solana/id.json \
  --recipient <YOUR_WALLET_ADDRESS>
# Expected output (post-SIMD-0432):
#   Closed Program Id <PROGRAM_ID>
#   Reclaimed X.XXX SOL to <YOUR_WALLET_ADDRESS>

# Step 5: Confirm the account is fully gone
solana account <PROGRAM_ID>
# Should return: "Error: AccountNotFound"
# Previously the account could linger with zero data but
# locked lamports — SIMD-0432 ensures full reclamation.

# Step 6: Verify your wallet received the lamports
solana balance
# e.g., 498.456 SOL  (increased by the reclaimed rent)

# =============================================================
# Programmatic Usage (Rust client example sketch)
# =============================================================
# // If you need to close a program from within a Rust client:
# // use solana_sdk::loader_v3::close_program instruction
# // (exact API depends on SDK version shipping SIMD-0432 support)
#
# let close_ix = solana_sdk::bpf_loader_upgradeable::close_any(
#     &program_id,
#     &recipient_pubkey,
#     &authority_pubkey,
#     &programdata_address,
# );
# let tx = Transaction::new_signed_with_payer(
#     &[close_ix],
#     Some(&payer.pubkey()),
#     &[&payer, &authority],
#     recent_blockhash,
# );
# rpc_client.send_and_confirm_transaction(&tx)?;
# // Lamports from both the program account and its programdata
# // account are now returned to `recipient_pubkey`.
```