MCP: ticket links and similar-ticket search (#113)

- get_ticket now returns `links` (blocks / blocked_by / relates_to /
  duplicates / duplicated_by, phrased from this ticket's side, limited to
  linked tickets the user can see) and `blocked` (any open blocked_by).
- find_similar_tickets (tickets:read): the possible-duplicates finder, by
  title or by an existing ticket (which is excluded from the results).
- link_tickets / unlink_tickets (tickets:write). Marking a duplicate only
  records the link. unlink also finds a link stored from the other side
  ("B blocked_by A" for "A blocks B").

api/ticket_dependencies.php's list/add/remove logic moves to
services/DependencyService.php, used by both (same checks and messages).
DependencyModel's remove methods now return rows removed, so removing a
link that is already gone no longer writes a "deleted" audit row.

Also includes the port in ToolScopeMiddleware's resource_metadata URL
(matches the 401's; no effect on prod, which has no port).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MGDKHiU5RJdo3dqQUDow3X

mcp/server.php

@@ -28,6 +28,8 @@ require_once dirname(__DIR__) . '/controllers/ApiTicketController.php';
 require_once dirname(__DIR__) . '/services/TicketCreationService.php';
 require_once dirname(__DIR__) . '/services/CommentService.php';
 require_once dirname(__DIR__) . '/services/AssignmentService.php';
+require_once dirname(__DIR__) . '/services/DependencyService.php';
+require_once dirname(__DIR__) . '/services/SimilarTicketService.php';
 
 use Laminas\HttpHandlerRunner\Emitter\SapiEmitter;
 use Mcp\Server;
@@ -138,7 +140,9 @@ $transport = new StreamableHttpTransport(
         new IdentityMiddleware($conn, $psr17, $psr17),
         new ToolScopeMiddleware(
             $psr17,
-            $canonical['scheme'] . '://' . $canonical['host'] . $metadata->getPrimaryMetadataPath()
+            $canonical['scheme'] . '://' . $canonical['host']
+                . (isset($canonical['port']) ? ':' . $canonical['port'] : '')
+                . $metadata->getPrimaryMetadataPath()
         ),
     ],
 );