docs: Use bech32 for AccountID across all docs and CLI output

[BrianSeong99]

Context

From devrel#126 feedback by @Dominik1999.

Problem

AccountIDs are displayed in hex format throughout docs and CLI output. Should use bech32 representation everywhere for consistency and usability.

Affected pages

• Quick Start CLI Basics (wallet output)
• Your First Smart Contract (deploy script output)
• All code examples that print AccountIDs

Also needs a corresponding issue in the client repo for CLI output changes.

[BrianSeong99]

Blocked on CLI changes — the docs show hex because the CLI outputs hex. Need to update client/midenup to output bech32 first, then update docs to match.

Tracking the CLI-side change separately.