fix(research): warn when unsupported --sort or --page/--limit flags are passed

[kome12]

Summary

Two `nansen research historical-*` subcommands silently ignored flags without any feedback to the caller:

• `historical-token-flow-summary` accepted `--page`/`--limit` in its CLI options but the handler never forwarded them to the API. Callers had no indication their pagination flags were being dropped.
• `historical-smart-money-balances` accepted `--sort` in its CLI options but the handler never forwarded it to the API. Callers had no indication their sort flag was being dropped.

Fix

Added `process.stderr.write()` warnings (matching the existing `⚠️` pattern used elsewhere in the codebase) that fire when the unsupported flag is detected:

• `historical-token-flow-summary` + `--page`/`--limit` → warns: `⚠️ warning: --page/--limit is ignored by historical-token-flow-summary (endpoint does not support pagination)`
• `historical-smart-money-balances` + `--sort` → warns: `⚠️ warning: --sort is ignored by historical-smart-money-balances (endpoint does not support order_by)`

Warnings go to stderr so they don't pollute JSON stdout output. The API call still succeeds — callers get data, plus a clear signal that the flag had no effect.

Tests

Added two regression tests in `src/tests/research.test.js`:

1. Calls `historical-token-flow-summary` with `--page 2 --limit 5` and asserts a matching warning was written to stderr.
2. Calls `historical-smart-money-balances` with `--sort value_usd:desc` and asserts a matching warning was written to stderr.

Both new tests pass alongside all 1475 existing tests (2 pre-existing skips unchanged).

Affected flag combinations

Subcommand	Silently ignored flag	Now warns
`historical-token-flow-summary`	`--page`, `--limit`	✓
`historical-smart-money-balances`	`--sort`, `--order-by`	✓

🤖 Generated with Claude Code

[kome12]

Closing — the fix approach was wrong. The correct fix is to reject the unsupported flags with a clear error rather than silently warning, since these flags have no effect at the API level.