Step 14: Connect components — chamishim karsay zahav

Three connections built and tested:
- Haskell Shoresh Engine via Erlang Port (JSON lines over stdin/stdout)
- Prolog Talmudic Engine via Unix domain socket (JSON over /tmp/shorashim/talmudic.sock)
- Erlang Sanhedrin via native BEAM calls

New: Server.hs (JSON-line server loop), json_bridge.pl + socket_server.pl
(Prolog socket interface), ShoreshEnginePort + TalmudicEngineSocket +
SanhedrinClient (Elixir GenServer wrappers). BereishitCycle now routes
unresolved cases through Talmudic Engine and Sanhedrin. All connections
gracefully degrade — pipeline falls back to L1 data when engines unavailable.

46 Elixir tests, 33 Haskell tests, 57 Prolog tests — 0 failures.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

talmudic_engine/src/interface/socket_server.pl

@@ -0,0 +1,145 @@
+%% socket_server.pl — Unix domain socket listener for Talmudic Engine.
+%%
+%% Construction §3.3: "JSON over Unix domain socket"
+%% Step 14 (Architecture §4): "Connect components"
+%%
+%% Listens on a Unix domain socket, accepts JSON requests,
+%% dispatches to api:process_request/2 via json_bridge,
+%% returns JSON responses.
+%%
+%% Protocol: One JSON object per line (same as Haskell server).
+%% Connection model: accept, handle one or more requests per
+%% connection, close when client disconnects.
+
+:- module(socket_server, [
+    serve/0,
+    serve/1,
+    stop_server/0
+]).
+
+:- use_module(library(socket)).
+:- use_module(library(json)).
+:- use_module(library(readutil)).
+
+:- use_module('../interface/api').
+:- use_module('../interface/json_bridge').
+
+%% Default socket path — dev path; production uses /var/run/shorashim/talmudic.sock
+default_socket_path('/tmp/shorashim/talmudic.sock').
+
+%% Dynamic flag to control server loop
+:- dynamic server_running/1.
+
+%% ============================================================
+%% SERVER ENTRY POINTS
+%% ============================================================
+
+%% serve/0 — Start server on default socket path
+serve :-
+    default_socket_path(Path),
+    serve(Path).
+
+%% serve/1 — Start server on given socket path
+serve(Path) :-
+    %% Clean up any stale socket file
+    (   exists_file(Path)
+    ->  delete_file(Path)
+    ;   true
+    ),
+    %% Ensure parent directory exists
+    file_directory_name(Path, Dir),
+    (   exists_directory(Dir)
+    ->  true
+    ;   make_directory_path(Dir)
+    ),
+    %% Create Unix domain socket
+    unix_domain_socket(ServerSocket),
+    tcp_bind(ServerSocket, Path),
+    tcp_listen(ServerSocket, 5),
+    format('Talmudic Engine listening on ~w~n', [Path]),
+    flush_output,
+    %% Set running flag
+    assert(server_running(true)),
+    %% Accept loop
+    accept_loop(ServerSocket, Path).
+
+%% Stop the server gracefully
+stop_server :-
+    retractall(server_running(_)).
+
+%% ============================================================
+%% CONNECTION HANDLING
+%% ============================================================
+
+%% Main accept loop — waits for connections
+accept_loop(ServerSocket, Path) :-
+    (   server_running(true)
+    ->  catch(
+            (   tcp_accept(ServerSocket, ClientSocket, _Peer),
+                tcp_open_socket(ClientSocket, InStream, OutStream),
+                %% Handle this client's requests
+                catch(
+                    handle_connection(InStream, OutStream),
+                    Error,
+                    (   format(user_error, 'Connection error: ~w~n', [Error]),
+                        flush_output(user_error)
+                    )
+                ),
+                close(InStream, [force(true)]),
+                close(OutStream, [force(true)]),
+                accept_loop(ServerSocket, Path)
+            ),
+            AcceptError,
+            (   format(user_error, 'Accept error: ~w~n', [AcceptError]),
+                flush_output(user_error),
+                %% Clean up
+                tcp_close_socket(ServerSocket),
+                (   exists_file(Path) -> delete_file(Path) ; true ),
+                fail
+            )
+        )
+    ;   %% Server stopped — clean up
+        tcp_close_socket(ServerSocket),
+        (   exists_file(Path) -> delete_file(Path) ; true ),
+        format('Talmudic Engine stopped.~n'),
+        flush_output
+    ).
+
+%% Handle a single connection — read lines until EOF
+handle_connection(InStream, OutStream) :-
+    read_line_to_string(InStream, Line),
+    (   Line == end_of_file
+    ->  true
+    ;   process_json_line(Line, ResponseJson),
+        %% Write JSON response on a single line
+        json_write_dict(OutStream, ResponseJson),
+        nl(OutStream),
+        flush_output(OutStream),
+        %% Continue reading from this connection
+        handle_connection(InStream, OutStream)
+    ).
+
+
+%% ============================================================
+%% JSON REQUEST PROCESSING
+%% ============================================================
+
+%% Process a JSON line string and produce a JSON response string
+process_json_line(Line, ResponseJson) :-
+    catch(
+        (   %% Parse JSON string to dict
+            atom_json_dict(Line, RequestDict, []),
+            %% Convert JSON to Prolog request
+            json_to_request(RequestDict, Request),
+            %% Dispatch to API
+            process_request(Request, Response),
+            %% Convert response to JSON
+            response_to_json(Response, ResponseJson)
+        ),
+        Error,
+        (   term_string(Error, ErrorStr),
+            ResponseJson = json{status: "error",
+                               error: json{code: "PROCESSING_ERROR",
+                                           message: ErrorStr}}
+        )
+    ).