v1.11.0 - Cleaner UI, repair surfacing, in-place reconfigure

This release closes most of the remaining Gold-tier quality scale rules. Four user-visible improvements:

Cleaner dashboard out of the box

• total_readings and last_reading_days are now flagged as diagnostic entities. Home Assistant relegates them to the Diagnostic block of the device card instead of mixing them with consumption sensors.
• current_month_litres and last_reading_litres are disabled by default. They are exact 1000x of their m³ counterparts, so the dashboard isn't doubled up. Users who prefer litres can enable them in Settings → Devices → Eaux de Marseille → [sensor].

If you want the previous behaviour, the litres sensors can be re-enabled in one click each.

Statistics import failures surface in HA

When async_import_historical_statistics fails (portal hiccup, recorder not ready, etc.), the integration now creates a repair issue in Settings → Repairs with a translated title and description, plus a Learn-more link. Previously these failures were silently logged. The issue clears itself automatically on the next successful import.

Reconfiguration without losing history

You can now change email, password, contract id or even provider in place, via the integration card's ⋮ menu → Reconfigure. Sensor history and imported statistics are preserved. Previously the only option was to delete and recreate the entry, which threw away years of data.

Implementation uses HA's _get_reconfigure_entry helper and _abort_if_unique_id_mismatch to refuse a swap to an already-configured contract.

Other

• Translations updated (English + French) including a new reconfigure step and issues section
• quality_scale.yaml updated: entity-category, entity-disabled-by-default, repair-issues, reconfiguration-flow all marked done

Verified

• Full local validation (ruff, mypy strict, pytest 30 passed)
• All 5 CI jobs green (Lint, Typecheck, Pytest, Hassfest, HACS)
• Live smoke test on a Raspberry Pi against SEM (Ventabren contract): auth + fetch + statistics path all green

Closes #13. Advances #14.