feat: order history & spending analytics sensors

[kwaczek]

Summary

• Order History Storage: Persistent JSON-based OrderStore with paginated API fetch for full order history backfill
• Spending Analytics Sensors: 10 new sensors for category spending (L0–L3) and per-item spending, each with "this year" and "all time" variants
• Config Flow: Two-step wizard (login → analytics) with opt-in checkboxes for analytics levels, configurable top N items (default 10), and hide discontinued products toggle
• Options Flow: All analytics settings reconfigurable on existing entries via the Configure button
• Background Processing: Full order history download and enrichment runs in the background without blocking the config flow
• Localized Notifications: Progress notifications during enrichment in EN/CS based on HA language setting

Test plan

• Production deployment tested with 484 orders
• Fresh Docker HA instance: full wizard flow (login → analytics → completion) works end-to-end
• Options flow: changing top N and hide discontinued works on existing entries
• Sensors correctly display top N items with total_count attribute
• Discontinued products excluded when hide option is enabled
• Background history fetch completes without blocking UI
• Verify on clean install without analytics enabled (base sensors only)

🤖 Generated with Claude Code

[dvejsada]

@kwaczek Thank you for this PR. However, please kindly add to make this (i.e. total history fetching and analytics) optional in the config with default being off - I would presume that may people (and I am one of them) do not want this kind of details to be fetched and stored in HA, incl. all history.

[kwaczek]

@dvejsada It is optional during the wizard and turned off by default. Spin off a new HA in docker and check the wizard