fix(auth): return clear error on missing auth header and handle configurable tus sign path

[Adityakk9031]

What kind of change does this PR introduce?

Bug fix / Developer Experience improvement

What is the current behavior?

Closes #1268

1. When a client sends a request to an authenticated endpoint without an Authorization header, the JWT authentication plugin (src/http/plugins/jwt.ts) extracted an empty string "" and attempted to verify it with jose.jwtVerify. This caused jose to throw an internal JWSInvalid: Invalid Compact JWS parsing error instead of an explicit error indicating that the authorization header is missing.
2. In src/http/routes/tus/lifecycle.ts, the signed URL check was hardcoded to /upload/resumable/sign rather than using the configured tusPath and SIGNED_URL_SUFFIX constants.

What is the new behavior?

1. jwtPlugin now checks for missing jwt and returns ERRORS.AccessDenied('Missing authorization header') instead of querying the database for JWT secrets and invoking verifyJWT with an empty string.
2. lifecycle.ts uses tusPath and SIGNED_URL_SUFFIX constants to support configured TUS URL paths in addition to the default /upload/resumable/sign.

[Adityakk9031]

@ferhatelmas have a look