Fix initialize.sh — missing max_supply argument in learn-token init

[DeFiVC]

What

The initialize.sh deployment script is missing the required --max_supply argument when initializing the learn-token contract, which will cause deployment to fail.

Why

The learn-token contract's initialize() function requires 6 arguments: admin, name, symbol, decimal, progress_tracker, and max_supply. The script only passes 5 — max_supply is omitted. Any deployment to testnet or mainnet will panic.

Scope

• Add the --max_supply argument to the learn-token initialization call in initialize.sh
• Prompt the operator for the value or use a reasonable default
• Ensure the value is passed in the correct format

Technical Context

• File: scripts/initialize.sh (lines ~149-162)
• The soroban contract invoke call for learn-token needs the missing argument
• Other contract initializations in the same script are correct

Acceptance Criteria

• initialize.sh passes --max_supply to the learn-token init call
• The script completes without error on a testnet deployment
• The value is configurable (e.g., via environment variable or prompt)