[Contract] Build Asset Tokenization Module

[yusuftomilola]

Implement fractional ownership of assets by tokenizing them. This enables multiple holders to own shares of a single asset.

Requirements

tokenize_asset(env, asset_id, symbol, total_supply, decimals, min_voting_threshold, tokenizer, name, description, asset_type)

• Creates a TokenizedAsset struct with the full token supply assigned to the tokenizer
• Stores token metadata (TokenMetadata)
• Records tokenizer as the sole initial holder

mint_tokens(env, asset_id, amount, minter) — Increases circulating_supply and minter's balance. Minter must be the tokenizer.

burn_tokens(env, asset_id, amount, burner) — Reduces supply and burner's balance.

transfer_tokens(env, asset_id, from, to, amount) — Validates transfer restrictions first. Updates balances of sender and receiver. Adds receiver to holders list if new.

Balance queries: get_token_balance, get_token_holders, get_tokenized_asset, calculate_ownership_percentage (returns basis points)

Valuation: update_valuation(env, asset_id, new_valuation)

Acceptance Criteria

• Total supply correctly tracked
• Holder list maintained (added on first receipt)
• calculate_ownership_percentage returns basis points (0–10000)