refactor: drop redundant webserver_impl::log_dispatch_error forwarder

There were two log_dispatch_error: the real free function
detail::log_dispatch_error(const webserver_config&, string_view) in
dispatch_util.cpp, and a one-line webserver_impl member that merely forwarded
to it (parent->config, msg). The member's only two callers were the v1 auth
alias hooks in webserver_aliases.cpp, which already have the owning webserver*
(ws_ptr) in scope — so they can call the free function directly with
ws_ptr->config.

Point those two call sites at detail::log_dispatch_error, drop the member
declaration (webserver_impl_dispatch.hpp) and its definition, and delete the
9-SLOC webserver_error_pages.cpp TU that existed solely to hold it. Removes a
duplicate function and a translation unit; no behavior change.

Local: builds, 113/113 tests pass, file-size + complexity + cpplint gates green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015tAodxYJMEY4VxCX4dk62e

Author: etr

src/Makefile.am

@@ -25,7 +25,7 @@ lib_LTLIBRARIES = libhttpserver.la
 # builds. The WS-off branch in websocket_handler.cpp provides stub
 # definitions (every member throws feature_unavailable except is_valid()
 # which returns false).
-libhttpserver_la_SOURCES = string_utilities.cpp webserver.cpp webserver_add_hook.cpp http_utils.cpp file_info.cpp http_request.cpp http_request_auth.cpp http_response.cpp http_response_factories.cpp http_resource.cpp create_webserver.cpp create_test_request.cpp websocket_handler.cpp hook_handle.cpp peer_address.cpp resource_hook_table.cpp cookie.cpp detail/http_endpoint.cpp detail/body.cpp detail/ip_representation.cpp detail/ip_access_control.cpp detail/ws_registry.cpp detail/hook_bus.cpp detail/route_table.cpp detail/daemon_lifecycle.cpp detail/dispatch_util.cpp detail/error_pages.cpp detail/hook_dispatcher.cpp detail/http_request_impl.cpp detail/http_request_impl_args.cpp detail/http_request_impl_tls.cpp detail/request_dispatcher.cpp detail/request_pipeline.cpp detail/response_materializer.cpp detail/upload_pipeline.cpp detail/websocket_upgrader.cpp detail/webserver_lifecycle.cpp detail/webserver_register.cpp detail/webserver_routes.cpp detail/webserver_routes_upsert.cpp detail/webserver_callbacks.cpp detail/webserver_dispatch.cpp detail/webserver_request.cpp detail/webserver_body_pipeline.cpp detail/webserver_error_pages.cpp detail/webserver_aliases.cpp 
+libhttpserver_la_SOURCES = string_utilities.cpp webserver.cpp webserver_add_hook.cpp http_utils.cpp file_info.cpp http_request.cpp http_request_auth.cpp http_response.cpp http_response_factories.cpp http_resource.cpp create_webserver.cpp create_test_request.cpp websocket_handler.cpp hook_handle.cpp peer_address.cpp resource_hook_table.cpp cookie.cpp detail/http_endpoint.cpp detail/body.cpp detail/ip_representation.cpp detail/ip_access_control.cpp detail/ws_registry.cpp detail/hook_bus.cpp detail/route_table.cpp detail/daemon_lifecycle.cpp detail/dispatch_util.cpp detail/error_pages.cpp detail/hook_dispatcher.cpp detail/http_request_impl.cpp detail/http_request_impl_args.cpp detail/http_request_impl_tls.cpp detail/request_dispatcher.cpp detail/request_pipeline.cpp detail/response_materializer.cpp detail/upload_pipeline.cpp detail/websocket_upgrader.cpp detail/webserver_lifecycle.cpp detail/webserver_register.cpp detail/webserver_routes.cpp detail/webserver_routes_upsert.cpp detail/webserver_callbacks.cpp detail/webserver_dispatch.cpp detail/webserver_request.cpp detail/webserver_body_pipeline.cpp detail/webserver_aliases.cpp
 # noinst_HEADERS: shipped in the tarball but NEVER installed under $prefix/include.
 # Detail headers (httpserver/detail/*.hpp) live here so they cannot leak to
 # downstream consumers — the public surface comes in through <httpserver.hpp>.

src/detail/webserver_aliases.cpp

@@ -64,6 +64,7 @@
 #include <utility>
 
 #include "httpserver/create_webserver.hpp"
+#include "httpserver/detail/dispatch_util.hpp"
 #include "httpserver/detail/method_utils.hpp"
 #include "httpserver/hook_action.hpp"
 #include "httpserver/hook_context.hpp"
@@ -244,12 +245,12 @@ void webserver::install_auth_alias_() {
                 try {
                     rejection = ws_ptr->config.auth_handler(*ctx.request);
                 } catch (const std::exception& e) {
-                    impl_ptr->log_dispatch_error(
+                    detail::log_dispatch_error(ws_ptr->config,
                         std::string("auth_handler threw: ").append(e.what())
                             .append("; failing closed with 500"));
                     auth_threw = true;
                 } catch (...) {
-                    impl_ptr->log_dispatch_error(
+                    detail::log_dispatch_error(ws_ptr->config,
                         "auth_handler threw unknown exception; "
                         "failing closed with 500");
                     auth_threw = true;

src/detail/webserver_error_pages.cpp

@@ -42,28 +42,11 @@
 
 // The 404/405/500 synthesis (not_found_page / method_not_allowed_page /
 // internal_error_page / run_internal_error_handler_safely) moved to the
-// error_pages behavior service (DR-014 §4.11); its webserver_impl forwarders
-// were removed once every caller became a service holding error_pages&
-// directly. Only log_dispatch_error survives below, still called from the v1
-// alias hooks (webserver_aliases.cpp).
-
-// Log @p msg via parent->config.log_error if a logger is configured.
-// Swallows any exception thrown by the logger -- dispatch must never
-// re-enter the catch from inside its own catch. Marked noexcept because
-// the outer catch(...) absorbs any bad_alloc from std::string(msg)
-// construction, so no exception can escape.
-//
-// @p msg is forwarded to the user
-// log_error callback UNCHANGED, regardless of
-// create_webserver::expose_exception_messages. The error log is the
-// canonical destination for verbatim exception text in v2; the HTTP
-// response body is the path that was sanitized. Handlers that may
-// throw exceptions containing sensitive data (DB connection strings,
-// credentials, attacker-influenced input) SHOULD catch and sanitize
-// the exception's what() before re-throwing if those values must not
-// appear in the server log either. See also @ref
-// internal_error_handler_t @security block in create_webserver.hpp.
-void log_dispatch_error(std::string_view msg) const noexcept;
+// error_pages behavior service (DR-014 §4.11), and the log_dispatch_error
+// member forwarder was removed once its last callers (the v1 alias hooks in
+// webserver_aliases.cpp) began calling the detail::log_dispatch_error free
+// function (dispatch_util.hpp, over the config bag) directly. No
+// webserver_impl error-page or log forwarder survives.
 
 // The lifecycle hook-firing helpers (the eleven per-phase fire_* and the
 // four gated fire_*_gated helpers) moved to the hook_dispatcher behavior