Add replayable debug reports.

A report dumps everything needed to understand a game that went wrong:
the full state (decks card by card, shop row and tier deck order,
discards, pending choices, banked Mana/Trumpets/apples), the round's
battles, and the whole event log. Available as JSON, which replays, or
text, which reads — and the text ends with a paste-ready repro test.

Battles now record the randomness they consume alongside what they
started from, so a result can be replayed long after the round cleared
those banks: same lineups, same dice, same events, down to the log text.
Results predating the recording say so rather than quietly re-rolling.

Three ways in: the 🐛 panel's download/copy buttons, GET
/api/debug/report (DEBUG-only, since a report holds both players' hands
and the shop deck order), and `mise run report`, which reads the
database directly so a live game can be dumped without DEBUG.

web/src/api.ts

@@ -32,6 +32,27 @@ export async function fetchCatalog(packs?: string[]): Promise<Card[]> {
   return (await res.json()) as Card[]
 }
 
+// debugReportURL builds the link to a game's debug report — the full state,
+// battles and event log, enough to replay the situation in a test. Served only
+// when the server runs with DEBUG on. `text` renders it for reading; otherwise
+// it downloads as JSON, which is the form a test can replay.
+export function debugReportURL(session: Session, format: 'json' | 'text', note?: string): string {
+  const params = new URLSearchParams({
+    game: session.gameId,
+    player: session.playerId,
+    token: session.token,
+    format,
+  })
+  if (note) params.set('note', note)
+  return `/api/debug/report?${params}`
+}
+
+export async function fetchDebugReportText(session: Session, note?: string): Promise<string> {
+  const res = await fetch(debugReportURL(session, 'text', note))
+  if (!res.ok) throw new Error('failed to fetch the debug report')
+  return res.text()
+}
+
 export function loadSession(): Session | null {
   try {
     const raw = localStorage.getItem(SESSION_KEY)

web/src/components/DebugPanel.tsx

@@ -1,20 +1,28 @@
 import { useEffect, useState } from 'react'
-import type { Card, ClientMessage } from '../types'
-import { fetchCatalog } from '../api'
+import type { Card, ClientMessage, Session } from '../types'
+import { debugReportURL, fetchCatalog, fetchDebugReportText } from '../api'
 import { CardView } from './CardView'
 
 interface Props {
   canGrant: boolean // shop phase — grants only land then
   packs: string[] // packs in play, so the catalog matches the game
+  session: Session // credentials for the debug report endpoint
   send: (msg: ClientMessage) => void
 }
 
-// DebugPanel is a testing aid (server DEBUG mode only): a collapsible drawer
-// listing every card in the packs in play, tier by tier. Clicking one drops it
-// into your deck for free, off-turn.
-export function DebugPanel({ canGrant, packs, send }: Props) {
+// DebugPanel is a testing aid (server DEBUG mode only). Two things live here:
+// a grab-any-card list of every card in the packs in play, tier by tier, and
+// the debug report — a dump of the whole game (both decks, the battles and their
+// dice, the event log) that can be replayed in a test.
+export function DebugPanel({ canGrant, packs, session, send }: Props) {
   const [open, setOpen] = useState(false)
   const [catalog, setCatalog] = useState<Card[]>([])
+  // What the report button last did, shown next to it and cleared on the next
+  // click — a report is silent otherwise, and copying especially so.
+  const [reportMsg, setReportMsg] = useState('')
+  // Travels with the report, so the dump itself says what looked wrong. Shared
+  // by both buttons: the download is a plain link and can't ask for it later.
+  const [note, setNote] = useState('')
 
   // Joined into a stable key so a fresh array identity each render doesn't refetch.
   const packKey = packs.join(',')
@@ -26,6 +34,17 @@ export function DebugPanel({ canGrant, packs, send }: Props) {
 
   const tiers = [...new Set(catalog.map((c) => c.tier ?? 0))].sort((a, b) => a - b)
 
+  const copyReport = async () => {
+    setReportMsg('…')
+    try {
+      const text = await fetchDebugReportText(session, note)
+      await navigator.clipboard.writeText(text)
+      setReportMsg('copied to the clipboard')
+    } catch {
+      setReportMsg('failed — is the server in DEBUG mode?')
+    }
+  }
+
   return (
     <div className={`debug-panel ${open ? 'is-open' : ''}`}>
       <button className="debug-toggle" onClick={() => setOpen((o) => !o)}>
@@ -33,6 +52,27 @@ export function DebugPanel({ canGrant, packs, send }: Props) {
       </button>
       {open && (
         <div className="debug-body">
+          <div className="debug-head">Debug report</div>
+          <div className="debug-report">
+            <input
+              className="debug-note"
+              value={note}
+              onChange={(e) => setNote(e.target.value)}
+              placeholder="What went wrong? (saved in the report)"
+            />
+            <a
+              className="debug-report-btn"
+              href={debugReportURL(session, 'json', note)}
+              onClick={() => setReportMsg('downloaded — replay it with rep.ReplayBattle(0)')}
+              download
+            >
+              ⬇ Download JSON
+            </a>
+            <button className="debug-report-btn" onClick={copyReport}>
+              📋 Copy as text
+            </button>
+            {reportMsg && <div className="muted">{reportMsg}</div>}
+          </div>
           <div className="debug-head">
             Buy any card
             {!canGrant && <span className="muted"> · only in the shop</span>}

web/src/components/Table.tsx

@@ -323,7 +323,12 @@ export function Table({ session, onLeave }: { session: Session; onLeave: () => v
       )}
       {error && <div className="toast">{error}</div>}
       {view.debug && (
-        <DebugPanel canGrant={view.phase === 'shop'} packs={view.packs} send={send} />
+        <DebugPanel
+          canGrant={view.phase === 'shop'}
+          packs={view.packs}
+          session={session}
+          send={send}
+        />
       )}
 
       {deckPeek &&

web/src/styles.css

@@ -3536,6 +3536,49 @@ h3 {
   margin-bottom: 8px;
 }
 
+/* The report buttons sit above the card list, small and out of the way — they
+   are used once a session, when something has already gone wrong. */
+.debug-report {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 6px;
+  margin-bottom: 12px;
+  padding-bottom: 12px;
+  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
+  font-size: 0.75rem;
+}
+
+.debug-report-btn {
+  background: rgba(255, 255, 255, 0.1);
+  color: var(--cream);
+  border: 1px solid var(--cocoa);
+  border-radius: 6px;
+  padding: 5px 8px;
+  font: inherit;
+  font-weight: 700;
+  text-decoration: none;
+  cursor: pointer;
+}
+
+.debug-report-btn:hover {
+  background: rgba(255, 255, 255, 0.2);
+}
+
+.debug-report .muted {
+  flex-basis: 100%;
+}
+
+.debug-note {
+  flex-basis: 100%;
+  background: rgba(0, 0, 0, 0.3);
+  color: var(--cream);
+  border: 1px solid var(--cocoa);
+  border-radius: 6px;
+  padding: 5px 8px;
+  font: inherit;
+}
+
 .debug-tier-label {
   color: var(--cream);
   font-size: 0.75rem;