feat(transaction): default generation to unix millis, allow override

[0xtristan]

Summary

• Reverts the microsecond default from fix(transaction): use microseconds for UniquenessData::Generation, not milliseconds #65; milliseconds are now the default, giving a ~5-second deduplication window with the sequencer's 5000-generation window
• Both UnsignedTransaction::builder() and Transaction::builder() accept an optional generation: u64 — omit it for the millis default, or pass any value (micros, a counter, a fixed test value)
• WASM builder exposes the same via .generation(bigint)

Rationale

With a 5000-generation window, microseconds gives a ~5ms deduplication window (too tight); milliseconds gives ~5s (practical). If the sequencer ever requires micros again, callers can pass duration.as_micros() as u64 / BigInt(Date.now()) * 1000n explicitly.

Test plan

• just check / just lint / just test (72/72 pass)

🤖 Generated with Claude Code

---

Summary by cubic

Default uniqueness generation now uses unix milliseconds, giving a ~5s deduplication window with the sequencer’s 5000-generation window. Added an optional override so callers can supply any generation value when needed.

• New Features
  • Rust: UnsignedTransaction::builder() and Transaction::builder() accept generation: u64 (optional). Omit to use current unix ms.
  • WASM: Added .generation(bigint) to override the default. README updated with an example.

^{Written for commit 5cedebd. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 3 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="wasm/README.md">

<violation number="1" location="wasm/README.md:119">
P2: The example is missing `await` before the builder chain, so `tx` is a `Promise` instead of the resolved result from `send(client)`.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: The example is missing await before the builder chain, so tx is a Promise instead of the resolved result from send(client).

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At wasm/README.md, line 119:

<comment>The example is missing `await` before the builder chain, so `tx` is a `Promise` instead of the resolved result from `send(client)`.</comment>

<file context>
@@ -111,6 +111,18 @@ const tx = Transaction.builder()
+value — for example a microsecond timestamp for a ~5ms window:
+
+```typescript
+const tx = Transaction.builder()
+    .callMessage(msg)
+    .generation(BigInt(Date.now()) * 1000n)  // microseconds
</file context>

Suggested change

	const tx = Transaction.builder()
	const response = await Transaction.builder()