sea-orm integration + rust-lightning persitence layer

[dcorral]

Summary

Replaces file-based persistence with SQLite database using sea-orm ORM.

Changes

New database tables:

• mnemonic - encrypted mnemonic storage
• kv_store - LDK persistence (channel manager, payments, swaps, network graph, scorer)
• config - configuration key/value pairs (indexer_url, proxy_url, etc.)
• revoked_token - revoked auth token IDs
• channel_peer - channel peer pubkey/address mapping

Migrated to database:

• Mnemonic (was encrypted file)
• All LDK KVStore data (channel manager, inbound/outbound payments, swaps, scorer)
• Config parameters (synced to files for rust-lightning compatibility)
• Revoked tokens (was flat file)
• Channel peer data (was flat file)
• PSBTs (temporary storage during channel funding)
• Output spender transactions

Architecture:

• Single shared DatabaseConnection via Arc
• SeaOrmKvStore implements rust-lightning's KVStoreSync trait
• Migrations run automatically on startup
• Config stored in DB as source of truth, synced to files for rust-lightning compatibility

rust-lightning submodule (961313c → b061470):

• RGB data persistence moved from filesystem to KVStoreSync trait across 8 files
• rgb_utils/mod.rs: replaced file I/O (read_rgb_transfer_info, write_rgb_transfer_info, parse_rgb_payment_info, get_rgb_channel_info_path) with KVStore namespace-based read/write operations using RGB_PRIMARY_NS + secondary namespaces (channel_info, payment_info_inbound, payment_info_outbound, transfer_info, etc.)
• ChannelContext, ChannelManager, OutboundPayments, KeysManager: added rgb_kv_store: Arc<dyn KVStoreSync + Send + Sync> field, threaded through constructors and deserialization
• color_commitment, color_htlc, color_closing: now take &dyn KVStoreSync instead of reading files directly
• is_channel_rgb, get_rgb_channel_info, rename_rgb_files, filter_first_hops, is_payment_rgb: switched from path-based lookups to KVStore reads
• Removed filesystem fallback — KVStore is now the sole persistence backend for RGB data

IMPORTANT!
This PR depends on RGB-Tools/rust-lightning#17 and .submodule must be updated to point to the right RGB-Tools fork before merging