Add a configurable max route-hop limit to `QuoteService.quote` to cap how many anchors a single quote can span

[Jagadeeshftw]

📌 Description

QuoteService.quote builds route: string[] by walking every anchor's liquidity entry for an asset, largest-first, until the requested amount is filled — with no limit on how many anchors can end up in the route. For an asset with many small-balance anchors, a single quote could return a route spanning dozens of anchors, which may be operationally awkward for whatever downstream settlement process ultimately has to coordinate with each one.

🧩 Requirements and context

• Add an optional maxRouteHops constructor parameter to QuoteService, defaulting to unlimited (preserving current behavior).
• When set and the fill would require more than maxRouteHops anchors, throw a 400/409 ApiError (pick and document the appropriate status) with a clear message rather than silently truncating the route and under-filling the amount.
• Wire the limit through config.ts/app.ts as an optional env-configurable value.

🛠️ Suggested execution

• Modify src/services/quoteService.ts's constructor and quote method to accept and enforce maxRouteHops.
• Add maxQuoteRouteHops to Config in src/config.ts, wired into the QuoteService construction in src/app.ts.
• Add tests in src/services/quoteService.test.ts for both the default (unlimited) and limited cases.

✅ Acceptance criteria

• With maxRouteHops unset, behavior is unchanged from today.
• With maxRouteHops set, a quote requiring more anchors than the limit fails clearly instead of silently under-filling.
• New tests cover both configurations.

🔒 Security notes

N/A — operational/performance safeguard; prevents unbounded route fan-out from a single quote request.

📋 Guidelines

• Minimum 95% test coverage
• Clear documentation
• Timeframe: 96 hours