feat: explainable activity log — reasons, subscriber names, snapshot gaps

The live activity feed flagged anomalies with no explanation and showed
opaque session keys. Make events self-describing and clickable.

- Clickable feed rows → read-only event-detail modal: humanized fields,
  entry/exit snapshots, and signed-chain provenance collapsed behind an
  audit disclosure (operator sees the story, auditor expands for crypto).
- Localized reason codes (backend i18n): the signed ledger now carries a
  stable REASON_CODE + params (+ English fallback) instead of free-text
  English. The UI translates via reason.<code> catalogs in sq/en, so an
  Albanian operator reads Albanian — from the same immutable event. Adding
  a language is a catalog change, no re-signing. (@parking/shared
  REASON_CODES, reasonPayload; entry/exit/subscription flows emit codes.)
- Subscriber-name resolution: a SUBSESS-… occurrence now shows the
  subscription holder's name (fallback "Abonent"/"Subscriber"). Resolved
  read-time server-side (events API + WS push) as a non-signed
  subscriberLabel; cached with invalidation on subscription edit/delete.
- Failed-snapshot visibility: a camera that was attempted but unreachable
  now shows a "⚠ camera unreachable" tile instead of a silent gap. The
  snapshots API returns failures[] from telemetry, filtered so a recovered
  capture shows no stale warning.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

apps/web/src/lib/i18n/en.ts

@@ -103,6 +103,67 @@ export const en: Catalog = {
     evtShiftZ: "SHIFT Z",
     evtCashMovement: "CASH",
     evtAnomaly: "ANOMALY",
+    // live-feed event detail line + classification badges (computed from payload)
+    evtNoReason: "no reason recorded",
+    badgeEntryRefused: "entry refused",
+    badgeExitRefused: "exit refused",
+    badgeLotFull: "lot full",
+    badgeBarrierFailed: "barrier did not open",
+    badgeManualOpen: "manual open",
+    badgeSubRefused: "subscription refused",
+    badgeNoTicket: "ticket not printed",
+    feedSourceBooth: "booth",
+    feedSourceReader: "reader",
+    // event-detail modal
+    eventDetail: "Event detail",
+    edType: "Type",
+    edTime: "Time",
+    edIndex: "Ledger index",
+    edDirection: "Direction",
+    edSource: "Source",
+    edIdentity: "Identity",
+    edReason: "Reason",
+    edSnapshots: "Snapshots",
+    edPayload: "Signed payload",
+    edChain: "Chain",
+    edSignature: "Signature",
+    edKeyId: "Key",
+    edPrevHash: "Prev hash",
+    edNoPayload: "No payload on this event.",
+    edCopy: "Copy",
+    edCopied: "Copied",
+    edDetails: "Details",
+    edAuditData: "Audit data (signature & chain)",
+    edAmount: "Amount",
+    edTender: "Tender",
+    edSession: "Session",
+    edPlate: "Plate",
+    edCategory: "Category",
+    edOperator: "Operator",
+    edTariffVersion: "Tariff version",
+    edRawPayload: "Raw signed payload",
+    edOccurrence: "Occurrence id",
+    subscriber: "Subscriber",
+  },
+  // Localized messages for the signed REASON_CODES (see @parking/shared). Keys MUST
+  // match the codes 1:1; {{param}} placeholders are filled from the event's
+  // reasonParams. Legacy events with no code fall back to the signed English `reason`.
+  reason: {
+    "entry.refused.full": "Entry refused — lot full ({{count}}/{{capacity}})",
+    "entry.held.noTicket": "Entry held — ticket not printed: {{detail}}",
+    "exit.refused.closed": "Exit refused — session already closed",
+    "exit.refused.noSession": "Exit refused — no open session for ticket",
+    "exit.refused.unpaid": "Exit refused — not paid (take payment first)",
+    "exit.refused.graceExpired": "Exit refused — walk-back grace expired (top-up required)",
+    "exit.open.noBarrier": "Exit recorded, but no exit barrier is configured — open manually",
+    "exit.open.unavailable": "Exit recorded, but the barrier is unavailable — open manually",
+    "exit.open.failed": "Exit recorded, but the barrier did not open — open manually",
+    "exit.freeGrace": "Free entry-grace (no charge)",
+    "exit.manualOpen": "Manual barrier open (human intervention)",
+    "sub.refused.notFound": "Subscription refused — not found",
+    "sub.refused.outOfWindow": "Subscription refused — {{status}}/out-of-window",
+    "sub.refused.noSession": "Subscription exit with no open session (already out / never entered)",
+    "sub.refused.atCapacity": "Subscription refused — at capacity ({{inUse}}/{{max}} cars in)",
   },
   tariff: {
     title: "Tariff",
@@ -446,5 +507,8 @@ export const en: Catalog = {
     reprinting: "printing…",
     noSnapshots: "no snapshots",
     loadingSnapshots: "loading snapshots…",
+    snapEntry: "entry",
+    snapExit: "exit",
+    snapFailed: "camera unreachable",
   },
 };