refactor: collapse mid-class #include fragment headers into parents

http_request.hpp and http_response.hpp split their class bodies across
mid-class #include fragments (http_request_auth.hpp, http_request_getters.hpp,
http_response_factories.hpp) purely to duck the old physical-line file-size
gate. Now that the gate measures SLOC, fold those declarations back inline so
each public class is one self-contained header. No behavioural change; the
matching .cpp translation units (http_request_auth.cpp, http_response_factories.cpp)
stay as separate compilation units. Parents are 149 / 132 SLOC after collapse.

The genuine encapsulation boundaries are untouched: detail::http_request_impl
(PIMPL) and the detail::body hierarchy behind http_response's SBO remain factored out.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: etr

src/Makefile.am

@@ -30,7 +30,7 @@ libhttpserver_la_SOURCES = string_utilities.cpp webserver.cpp webserver_add_hook
 # Detail headers (httpserver/detail/*.hpp) live here so they cannot leak to
 # downstream consumers — the public surface comes in through <httpserver.hpp>.
 noinst_HEADERS = httpserver/string_utilities.hpp httpserver/detail/modded_request.hpp httpserver/detail/http_endpoint.hpp httpserver/detail/body.hpp httpserver/detail/webserver_impl.hpp httpserver/detail/webserver_impl_dispatch.hpp httpserver/detail/connection_state.hpp httpserver/detail/secure_zero.hpp httpserver/detail/http_request_impl.hpp httpserver/detail/resource_hook_table.hpp httpserver/detail/route_entry.hpp httpserver/detail/lambda_resource.hpp httpserver/detail/segment_trie.hpp httpserver/detail/route_cache.hpp httpserver/detail/route_tier.hpp httpserver/detail/unescape_helpers.hpp gettext.h
-nobase_include_HEADERS = httpserver.hpp httpserver/body_kind.hpp httpserver/cookie.hpp httpserver/constants.hpp httpserver/create_webserver.hpp httpserver/create_webserver_setters.hpp httpserver/create_test_request.hpp httpserver/webserver.hpp httpserver/webserver_routes.hpp httpserver/webserver_runtime.hpp httpserver/webserver_websocket.hpp httpserver/webserver_hooks.hpp httpserver/websocket_handler.hpp httpserver/http_utils.hpp httpserver/http_utils_helpers.hpp httpserver/ip_representation.hpp httpserver/file_info.hpp httpserver/http_request.hpp httpserver/http_request_auth.hpp httpserver/http_request_getters.hpp httpserver/http_response.hpp httpserver/http_response_factories.hpp httpserver/http_resource.hpp httpserver/feature_unavailable.hpp httpserver/iovec_entry.hpp httpserver/http_arg_value.hpp httpserver/http_method.hpp httpserver/hook_phase.hpp httpserver/hook_action.hpp httpserver/hook_handle.hpp httpserver/hook_context.hpp
+nobase_include_HEADERS = httpserver.hpp httpserver/body_kind.hpp httpserver/cookie.hpp httpserver/constants.hpp httpserver/create_webserver.hpp httpserver/create_webserver_setters.hpp httpserver/create_test_request.hpp httpserver/webserver.hpp httpserver/webserver_routes.hpp httpserver/webserver_runtime.hpp httpserver/webserver_websocket.hpp httpserver/webserver_hooks.hpp httpserver/websocket_handler.hpp httpserver/http_utils.hpp httpserver/http_utils_helpers.hpp httpserver/ip_representation.hpp httpserver/file_info.hpp httpserver/http_request.hpp httpserver/http_response.hpp httpserver/http_resource.hpp httpserver/feature_unavailable.hpp httpserver/iovec_entry.hpp httpserver/http_arg_value.hpp httpserver/http_method.hpp httpserver/hook_phase.hpp httpserver/hook_action.hpp httpserver/hook_handle.hpp httpserver/hook_context.hpp
 
 AM_CXXFLAGS += -fPIC -Wall
 

src/http_request_auth.cpp

@@ -21,9 +21,7 @@
 // http_request public-API forwarders for the auth/credentials surface:
 // get_user / get_pass / get_digested_user, check_digest_auth /
 // check_digest_auth_digest, and the high-level TLS / client-certificate
-// accessors. The declarations live in httpserver/http_request_auth.hpp
-// (included by httpserver/http_request.hpp via the in-class-body
-// include pattern).
+// accessors. The declarations live in httpserver/http_request.hpp.
 
 #include "httpserver/http_request.hpp"
 

src/http_response_factories.cpp

@@ -290,7 +290,7 @@ http_response http_response::unauthorized(digest_challenge challenge) {
     return r;
 }
 #else  // !HAVE_DAUTH
-// The declaration in http_response_factories.hpp is
+// The declaration in http_response.hpp is
 // unconditional, so a HAVE_DAUTH-off build must still define this overload
 // rather than leave it as a link error. Throw feature_unavailable instead
 // of constructing a response.