#108 Feature: Implement Lightning Address

[andycreed0x]

Purpose

Implement Lightning Address support for JAN3/AQUA users. Closes #108 Feature: Implement Lightning Address.

Each user gets a Lightning Address (username@domain) backed by a rotating pool of Liquid receive addresses registered with the AQUA backend. The wallet↔account binding is maintained via a fingerprint hash.

Main Changes

• ✨ Added jan3_user_info — fetch account profile; auto-tops-up LN address pool when active
• ✨ Added jan3_enable_lightning_address — toggle LN-address delivery; populates address pool on enable
• ✨ Added jan3_ln_check_username / jan3_purchase_ln_username — check availability and buy/update a Lightning Address username (funded via signed L-BTC tx)
• ✨ Added jan3_rebind_wallet — re-register the wallet↔account binding (fingerprint + email hash)
• ♻️ Expanded Jan3AccountsManager with register_ln_addresses, ensure_ln_pool, rebind_wallet, purchase_ln_username
• 🗃️ WalletData gains next_address_index for sequential, non-reusing address handouts
• ✅ Tests for all new tools, manager methods, CLI commands, and storage migration

Checklist

• No hardcoded values (they should go in constants.py, .env, or our database)
• Added/updated tests (if necessary)
• Added/updated relevant documentation (if necessary)

[andycreed0x]

Changes made on top of the LN Addresses branch

• Ported CLI commands for everything that was already implemented in the MCP.
• Unified aqua_* and jan3_* tools. The old branch had independently re-unified the same account/session logic that develop already rewrote in JAN3 Account creation through captchaless login #101, so a rebase would have produced conflicts across every account file and ~2,300 test lines — and still left a two-manager split to clean up. It was faster and cleaner to re-port just the net-new LN logic (~600 lines) directly onto develop's unified Jan3AccountsManager.
• Implemented jan3_rebind_wallet tool — redirects the LN address to a new wallet.
• Automatic Liquid address pool refill for LN addresses, instead of prompting the user.
• Peek address logic. Some flows always require a fresh address; others can reuse an existing one. This distinction matters: if too many unused addresses accumulate, the agent can easily hit Blockstream's rate limit just from wallet sync operations.
• Wallet identification now uses the descriptor fingerprint in addition to the wallet name.
• Cleaned up incorrect password assumptions — Claude had assumed a password was required for all operations, including address generation.
• Cleaned up incorrect payment assumption — Claude had assumed the user needed to pay to obtain their first LN address.
• LN address purchase flow now prompts the user before proceeding, and accepts both USDT and LBTC. Previously it ran silently with incomplete fields.