tronscan: fix data loss in transaction/transfer pagination

[KyJIJIEP]

Summary

This PR fixes three pagination issues in the tronscan plugin that can cause operations to be silently dropped during sync, and aligns the plugin with the current limits of apilist.tronscanapi.com.

All changes are confined to src/plugins/tronscan/api.ts. Behaviour, converters and the public method signatures are unchanged.

Background

Tronscan's public API (apilist.tronscanapi.com) enforces limits that the plugin did not account for:

1. List endpoints enforce start + limit <= 10000 per (address, time-range) query (max 50 records per page); paging past that ceiling is silently capped. This applies to transaction, token_trc20/transfers and transfer/trx alike — see the official docs.
2. The account/tokens endpoint caps limit at 200 (default 20), per the official docs.

In addition, transfer/transaction list endpoints may return fewer rows per page than the requested limit (e.g. the long-standing behaviour of token_trc20/transfers, see tronscan/tronscan-api#59).

Problems fixed

1. account/tokens requested limit: 999 — above the documented maximum of 200, so the request may be rejected or truncated. Lowered to 200.

2. Records beyond the start + limit <= 10000 ceiling were lost. The previous loops paged by start and stopped when start + limit >= total. For an active wallet whose history within the requested range exceeds that ceiling, everything past it was never fetched. Now we page within a time window and, once a window reaches the ceiling, move its upper bound (end_timestamp) back to the oldest record we have seen and continue — so the full history is retrieved without gaps. A window stops as soon as it returns fewer records than the cap, so wallets below the ceiling cost exactly one pass.

3. Rows between pages could be skipped. The cursor advanced by the requested limit (50). When Tronscan returned fewer rows than requested for a page, the next start jumped past the un-returned rows. The cursor now advances by the number of records actually returned.

Implementation

The three list methods (fetchTransactions, fetchTokenTransfers, fetchTronTransfers) now share a single typed fetchPaginated<Body, Item> helper that:

• pages within a time window, advancing start by the actual returned count;
• de-duplicates by record id (Set), so the boundary record re-fetched when the window narrows is not counted twice;
• narrows the window via end_timestamp only when a window hits the start + limit <= 10000 ceiling, and guards against making no progress (records sharing a timestamp).

Testing

• ts-standard src/plugins/tronscan/api.ts — passes (0 issues)
• tsc --noEmit — passes (0 errors)

There are no existing unit tests for this plugin (no converters change here), so none were added; the change is isolated to the API/pagination flow per the repo's layering guidelines.