Phone runtime (2b): inventory phone on the board dials for real

The phone gains a session mode that reads the live directory (/phone) and
dials (/dial); the inventory threads it through. On a campaign level the
board shows an INVENTORY nav button that opens the tool rack, and connecting
a call hands back to the campaign via /?resume=1 (a fast-path that resumes
the current node instead of the splash). On Barricelli's note-board: open
inventory -> phone -> dial 5550100 -> Glitch Hunter.

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

src/play.tsx

@@ -41,6 +41,13 @@ export function Play() {
         if (!cancelled) res.ok ? apply(await res.json()) : setStatus('NODE NOT FOUND')
         return
       }
+      // ?resume=1 (e.g. handed back from the in-board phone) drops straight into the
+      // current node instead of the splash.
+      if (new URLSearchParams(window.location.search).has('resume')) {
+        const res = await fetch('/api/playthroughs/current')
+        if (cancelled) return
+        if (res.ok && res.status !== 204) { apply(await res.json()); return }
+      }
       // The bare root is always the front door: list the playable cases, and offer
       // Resume on the one already in progress rather than auto-resuming into it.
       const [cases, current] = await Promise.all([fetch('/api/mysteries'), fetch('/api/playthroughs/current')])