Fixes#2180Fixes#2181
Migrate the gateway from Fiber v2 to Fiber v3.3.0 and update the affected server, middleware, handler, controller, and test code for the new APIs.
Replace the deprecated Fiber filesystem middleware used by the WebUI with the Fiber v3 static middleware, serving the embedded WebUI assets from an fs.Sub filesystem.
Fix the request header limit handling regression by adding a temporary handler for Fiber v3/fasthttp small-buffer errors so oversized request headers return the expected regulated S3 error response.
Fix the debuglogger panic by reworking the boxed key/value formatter used for debug request and response dumps. The formatter now handles long header keys and values without producing invalid wrap widths, negative padding, or out-of-range string slices.
Fiber includes a built-in panic recovery middleware that catches panics in route handlers and middlewares, preventing the server from crashing and allowing it to recover. Alongside this, a stack trace handler has been implemented to store system panics in the context locals (stack).
Both the S3 API server and the Admin server use a global error handler to catch unexpected exceptions and recovered panics. The middleware’s logic is to log the panic or internal error and return an S3-style internal server error response.
Additionally, dedicated **Panic** and **InternalError** loggers have been added to the `s3api` debug logger to record system panics and internal errors in the console.
The buildSearchFilter function doesn't need to be exported, and
can use strings.Builder. Add a unit test to make sure this didn't
change any logic.
This will also use the debuglogger to enable debugging.
The debuglogger should be a top level module since we expect
all modules within the project to make use of this. If its
hidden in s3api, then contributors are less likely to make
use of this outside of s3api.