perf: remove dead redirect middleware (ran on every request doing nothing)

The redirect middleware was a leftover from the custom HTTP server → Axum
migration. It executed on every single request (including static files),
allocating a String from the URI path and performing 3 starts_with() checks,
but never actually redirected anything — just debug logging.

- Remove middleware application from main.rs
- Remove pub mod redirect from middleware/mod.rs
- Delete redirect.rs (121 lines of dead code)

Saves ~80-170ns of overhead per request (String alloc + comparisons +
Tower layer dispatch).

src/interfaces/middleware/mod.rs

@@ -1,2 +1 @@
 pub mod auth;
-pub mod redirect; // Add redirect middleware for API to Axum transition