feat: store explanations and votes on them in an Azure table

[andig]

on top of #214, pairs with evcc-io/evcc#34926

Lets the caller vote on an explanation, so the prompt can be tuned from what users found wrong. The service stays stateless until a user votes: /optimize/explain stores nothing and answers with the explanation alone.

• POST /optimize/explain/feedback takes the same payload as /optimize/explain plus explanation, vote: up|down and an optional comment, and stores that as one row: the digest the model saw (gzip, split below the 64 KiB property limit), prompt hash, model, answer, vote, comment, language, plan features to group by (status, steps, horizon, vehicles, batteries, strategy, departure masses, goals, demands) and the sponsor subject as a hash. 503 without a store, 502 when the store fails.
• Storage is an Azure table, explanations in a new stoptimizerfeedback account; the container app writes with its managed identity (Storage Table Data Contributor), OPTIMIZER_FEEDBACK_TABLE_ENDPOINT in the bicep. OPTIMIZER_FEEDBACK_CONNECTION_STRING for Azurite and local runs. Nothing to put in the key vault.
• feedback.rows() reads the table back with the digests unpacked, for the analysis tooling.
• Go client regenerated for the new route, azure-data-tables and azure-identity added.

Tests cover the round trip of long digests, the stored row, incomplete votes, that explain stores nothing, unconfigured store, store failure. The bicep builds.

• update ui, docs and privacy policy to explain data collection.
  • privacy policy: Privacy policy: plan explanations and feedback on them evcc.io#62
  • docs: Optimizer: data is only stored on feedback to a plan explanation docs#1224
  • ui, privacy link: Optimizer: explain the plan through the optimizer service evcc#34920
• store only on feedback
• data cleanup after 6 or 12 month (GDPR)

🤖 Generated with Claude Code

[naltatis]

Stores every explanation

Lets make this less intrusive and only store explanations (+ data) where the user intentionally provided feedback. This is more in line with expected user expectation since the optimizer is otherwise stateless and we otherwise store nothing without explicit consent.

[andig]

Done in 8e15737: /optimize/explain stores nothing and returns no id any more. /optimize/explain/feedback takes the explain payload plus explanation, vote and comment, and only that is stored. evcc side in evcc-io/evcc#34926.

🤖 Generated with Claude Code