fix(typescript): build Router event markets as MarketList - #2111

Fixes #2074

What was broken

Router's local convertEvent() in sdks/typescript/pmxt/router.ts built markets as a plain array, while UnifiedEvent.markets is declared as MarketList (an Array subclass with a .match(query) helper). Any caller doing result.event.markets.match(...) or result.markets.match(...) on data from Router.fetchEventMatches or Router.fetchMatchedEventClusters got TypeError: ...match is not a function, despite the type system promising MarketList. Python has no equivalent bug because router.py reuses the single _convert_event from client.py.

What changed

router.ts now builds the markets array with MarketList.from((raw.markets || []).map(convertMarket)) as MarketList, exactly matching the canonical converter in client.ts. This covers both call sites that use the local converter (fetchEventMatches and fetchMatchedEventClusters). No other behavior changes; the per-venue converters in client.ts are untouched.

Tests

Added sdks/typescript/tests/router-event-markets.test.ts following the existing router-sql-orderbook.test.ts fetch-spy pattern:

• fetchEventMatches returns results whose .markets and .event.markets are both MarketList instances and on which .match() resolves the expected market.
• fetchMatchedEventClusters returns clustered events whose markets are also MarketList.

Both tests fail without the fix (TypeError / not instanceof MarketList) and pass with it.

Verification

• Full TypeScript SDK suite: 18 suites, 95 tests, all passing.
• bash scripts/verify-all.sh on this branch: core jest 48/52 suites pass, python SDK 265 passed. The only failures are three pre-existing Windows-environment sandbox defects that fail identically on a clean checkout of main before any change of mine (core test/server/pmxt-ensure-server.test.ts plus two HOME-based sdks/python/tests/test_server_manager.py cases; they set env HOME but Node and Path.home() read USERPROFILE on win32). Upstream CI runs ubuntu-latest where these pass.