App 2.19.7: meter AC charging too, while the app runs

A session runs whenever power flows into the pack, AC or DC; gaps the
head unit slept through are dropped as before. Dashboard and server
texts no longer say DC only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

server/README.md

@@ -38,7 +38,7 @@ with (403 otherwise); the shared token works for any.
   and the answer is `200 {stored, droppedCount, dropped}`, even when nothing was usable, since
   the car would only send it again.
 - `PUT /v1/consumption/daily` — one delta chunk of a day's consumption.
-- `PUT /v1/charging-sessions/{sessionId}` — a finished DC session with its curve.
+- `PUT /v1/charging-sessions/{sessionId}` — a finished charging session (AC or DC, as far as the car was awake) with its curve.
 - `GET /v1/consumption/history/{installationId}` — the car reads its own totals back.
 - `GET /v1/health` — `{"status":"ok"}`.