fix(sdk): restore the build — undefined event type names

[arkhindi12]

main does not compile.

$ npx tsc --noEmit
src/events.ts(569,32): error TS2552: Cannot find name 'TopUpEvent'.
src/events.ts(573,32): error TS2304: Cannot find name 'ClawbackEvent'.

$ npm run build
src/events.ts(569,32): error TS2552 ...

StreamHistoryEntry references TopUpEvent and ClawbackEvent, but
events.ts imports neither. Both names exist in types/index.ts only as
deprecated aliases of StreamTopUpEvent / StreamClawbackedEvent, so this
uses the current names directly rather than importing the deprecated ones.

No runtime change — the aliases are the same types, and the kind
discriminants are untouched.

Knock-on effect

npm ci fails too, because the prepare script runs npm run build:

npm error command sh -c npm run build
npm error code 2

So every contributor hitting a fresh clone, and every PR's CI, is red on
main for a reason unrelated to their change.

Verification

$ npx tsc --noEmit            # before: 2 errors   after: rc=0
$ npm run build               # before: fails      after: rc=0
  created dist/esm in 3.3s
  created dist/cjs in 2.7s

[arkhindi12]

@Jaydbrown — one ordering question before you spend time reviewing, since CONTRIBUTING requires CI green.

main does not build at 1e46b52: src/events.ts references TopUpEvent and ClawbackEvent, which it never imports (they exist only as deprecated aliases in types/index.ts). This PR is the two-line fix, and with it applied locally:

npx tsc --noEmit   → rc=0
npm run build      → rc=0 (dist/esm, dist/cjs, dist/types)

The other three PRs I opened (#1006, #1007, #1008) branch from main, so their npm run build stays red until this lands. Their own test suites pass (8, 10 and 7 tests respectively) and nothing in them touches events.ts — the failure is purely the pre-existing one.

Two ways to sequence it, whichever suits you:

1. Merge this first, then re-run CI on the other three — once main carries the fix, their merge commits should go green without further changes from me.
2. I rebase fix(sdk): retry transient 5xx on read-only RPC calls #1006–feat(sdk): add futurenet and standalone network config #1008 onto this branch so each one is self-contained and green on its own. Say the word and it is a few minutes' work.

Also worth flagging: all four CI runs are sitting at action_required (first contribution from this fork), so they need an approve-and-run before they report anything at all.