Compute the 24h price change when a provider does not send it

[DRadmir]

Why

CoinGecko and other providers often send no 24h price change for smaller coins. The server saved it as 0, so the app showed "0.00%" even when the price had moved a lot, and price change alerts for those coins never fired.

What changed

• A missing 24h change is no longer saved as 0.
• When a price update arrives without it, the server computes it from its own price history 24 hours earlier, as it already did for Pyth and DefiLlama.
• This now happens when prices are saved, so the separate job that did it every 5 minutes is removed.
• The app gets the same response as before.

Also in this PR

• The 24h change rule lives in PriceClient. The price adapter exposes get_chart_prices(price_ids, from, until), and PriceClient::store_prices fills in a missing change before saving. Covered by test_store_prices_fills_a_missing_24h_change_from_the_price_a_day_ago.
• No function outside storage takes a DatabaseClient. The 17 helpers that did (assets, nft, prices, setup dev seed, rewards units.rs) became one of:
  • a storage method (get_nft_asset, get_referral_use_facts, get_abuse_facts);
  • a pure mapper or rule;
  • a port method the service composes.
• Rewards behaviour is unchanged. Each reward step runs the same queries in the same order. apply_referral_code now returns the decision, and the service calls set_referral.
• Every storage update is update_x(filters, updates). Each filter enum implements QueryFilter, so reads and updates share one condition. AssetFilter::ExcludeIds replaces reading and diffing id sets for the image, price and fiat flags, and the fiat port no longer takes function pointers.
• Five verbs for every storage and port method: get, add, set, update, delete. Port reads are get_*.
• The rules are written down and enforced. core/skills/architecture.md (Repository Pattern) states them, and just check-boundaries adds two rules: only storage takes a DatabaseClient, and repository methods use the five verbs.

Checks

Check	Result
services tests	156 pass
storage tests	17 pass
swapper tests	364 pass
primitives tests	209 pass
Storage database tests (local Postgres)	11 pass
Clippy and just lint	0 warnings
cargo check --workspace --all-features --tests	builds
Repo checks	all pass

The flag updates and the wallet-transactions query were also checked by hand against Postgres.