🚦 fix: ERR_ERL_INVALID_IP_ADDRESS and IPv6 Key Collisions in IP Rate Limiters (#12319)

* fix: Add removePorts keyGenerator to all IP-based rate limiters

Six IP-based rate limiters are missing the `keyGenerator: removePorts`
option that is already used by the auth-related limiters (login,
register, resetPassword, verifyEmail). Without it, reverse proxies that
include ports in X-Forwarded-For headers cause
ERR_ERL_INVALID_IP_ADDRESS errors from express-rate-limit.

Fixes #12318

* fix: make removePorts IPv6-safe to prevent rate-limit key collisions

The original regex `/:\d+[^:]*$/` treated the last colon-delimited
segment of bare IPv6 addresses as a port, mangling valid IPs
(e.g. `::1` → `::`, `2001:db8::1` → `2001:db8::`). Distinct IPv6
clients could collapse into the same rate-limit bucket.

Use `net.isIP()` as a fast path for already-valid IPs, then match
bracketed IPv6+port and IPv4+port explicitly. Bare IPv6 addresses
are now returned unchanged.

Also fixes pre-existing property ordering inconsistency in
ttsLimiters.js userLimiterOptions (keyGenerator before store).

* refactor: move removePorts to packages/api as TypeScript, fix import order

- Move removePorts implementation to packages/api/src/utils/removePorts.ts
  with proper Express Request typing
- Reduce api/server/utils/removePorts.js to a thin re-export from
  @librechat/api for backward compatibility
- Consolidate removePorts import with limiterCache from @librechat/api
  in all 6 limiter files, fixing import order (package imports shortest
  to longest, local imports longest to shortest)
- Remove narrating inline comments per code style guidelines

---------

Co-authored-by: Danny Avila <danny@librechat.ai>

api/server/middleware/limiters/forkLimiters.js

@@ -1,6 +1,6 @@
 const rateLimit = require('express-rate-limit');
-const { limiterCache } = require('@librechat/api');
 const { ViolationTypes } = require('librechat-data-provider');
+const { limiterCache, removePorts } = require('@librechat/api');
 const logViolation = require('~/cache/logViolation');
 
 const getEnvironmentVariables = () => {
@@ -59,6 +59,7 @@ const createForkLimiters = () => {
     windowMs: forkIpWindowMs,
     max: forkIpMax,
     handler: createForkHandler(),
+    keyGenerator: removePorts,
     store: limiterCache('fork_ip_limiter'),
   };
   const userLimiterOptions = {