feat: packet inspector detail for non-raw packets

[sg]

What changed

• The Packets-screen Inspector now renders full details for non-raw packets (ADVERT, CMD_ACK, CONTACT, CONTACTS_SYNC, ACK, REPEAT/NO_REPEAT, etc.) instead of "no raw bytes for this packet".
• New PacketDetail.vue shows, per selected row:
  • A one-line description of what the event is and what the bot does with it.
  • Packet — the indexed envelope fields the bot extracted (time, type, channel, sender, pubkey, path/hops, SNR/RSSI, text), omitting unset ones.
  • Payload — parsed payload_json (the raw library event payload).
  • Attributes — parsed attributes_json when present.
• Packets.vue fetches the full row via GET /api/packets/{id} for non-raw rows (the list view omits the JSON blobs); raw packets keep the existing hex breakout.

Why

The inspector previously only worked for RX_LOG raw frames; every other packet type showed a dead-end message even though the data (payload_json/attributes_json + envelope columns) was already stored. This surfaces what the bot is doing/seeing for each event.

Breaking changes

None. Frontend-only; no API or schema changes. Rebuilt webapi/static/ assets included.