Phone runtime (2a): connected directory + dial resolution

GET /playthroughs/:id/phone returns the directory of the phone node the
current node is wired to; POST /playthroughs/:id/dial resolves a number to
connect (advance to the wired dialogue), voicemail (known contact, no line
here), or not-in-service. Barricelli's note-board is wired to the phone node
and Glitch Hunter's decline returns to it. Frontend (inventory on the board)
is 2b.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

mysteries/barricelli-files/mystery.json

@@ -141,6 +141,11 @@
               "key": "report_back",
               "label": "Call Glitch Hunter",
               "to": "hunter-intro"
+            },
+            {
+              "key": "phone",
+              "label": "Phone",
+              "to": "phone"
             }
           ]
         },
@@ -174,7 +179,7 @@
             {
               "key": "decline",
               "label": "Back",
-              "to": "dobby-tasks"
+              "to": "note-board"
             }
           ],
           "utterances": [