fix(hono): change syncFacilitatorOnStart default to false for serverless compatibility

[lau90eth]

Fixes #2157

Problem

paymentMiddleware() had syncFacilitatorOnStart: true as default, causing cold-start timeouts on serverless/edge environments (Cloudflare Workers, AWS Lambda).

On every cold isolate, the middleware would block the first request while fetching facilitator support data via getSupported(), producing 10–15s latencies that caused discovery probes (e.g. x402scan) to time out and mark routes as invalid.

Root cause

The accepts and extensions data needed to emit a 402 response is already known from route configuration — facilitator initialization is only required at verify/settle time, not for the initial 402 response.

Fix

Change the default to false to enable lazy initialization: the facilitator is contacted only when an actual payment needs to be verified, not on every cold start.

Users who need eager initialization (e.g. long-running servers) can still pass syncFacilitatorOnStart: true explicitly.

Changes

• index.ts: changed default from true to false in all 3 exported functions (paymentMiddlewareFromHTTPServer, paymentMiddleware, paymentMiddlewareFromConfig) and updated JSDoc
• index.test.ts: updated retry test to pass syncFacilitatorOnStart: true explicitly since it tests behavior specific to that mode

Testing

All 36 tests pass.

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[phdargen]

Thanks for the contribution @lau90eth but this wont fix the issue, see #2157 (comment)

[lau90eth]

Reopened as #2221 with the proper fix as suggested — root cause was in buildPaymentRequirements() in @x402/core, not just the default change. Thanks for the detailed feedback.