startSubscription

Start subscription for an address with automatic reconnection.

Incremental by default. Previous behavior wiped the local UTXO cache and sync state on every subscription start, causing a visible zero-balance flicker at every app launch. Now the default path resumes from the last saved transactionId — full resync only happens when forceFullResync is true (Developer options) or a later round detects a reorg / unknown-txId signal from the indexer.

Flow:

1. Read saved lastProcessedTransactionId from SyncStateManager.

2. Subscribe from that ID (null = new address, replay from genesis).

3. Process each update via UtxoManager.

4. Save progress after each Progress update (throttled).

5. On error: retry with exponential backoff.

Resumption:

• First sync for an address: saved ID is null → replay all history.

• Warm launch: saved ID present → resume from it, no wipe, no flicker.

Reconnection:

• Network errors: retry with exponential backoff (1s, 2s, 4s, 8s, 16s, 32s max).

• After max retries: emit error state and stop (caller must restart subscription).

• Retryable errors: IOException, connection failures, WebSocket errors.

• Non-retryable errors: CancellationException (user cancelled).

Force re-sync entry point (Developer Options). A UI-level "Force re-sync" button should cancel the currently-collecting Flow first, then re-call startSubscription(address, forceFullResync = true). That wipes local state once (not on every retry) and re-subscribes from genesis. No separate public forceFullResync(address) method — the flag on this function is the single authoritative entry point.

Parameters