Implement repricing flow and service rate fixes

[roncodes]

Summary

• implement the repricing flow around order.purchase_rate_uuid as the canonical applied pricing link
• create and attach a fresh purchase rate + transaction on quote application, then void the superseded transaction
• fix service rate calculation and editing gaps across per-meter, parcel, per-drop, and algorithm-based pricing
• prevent the order details route from tearing down when switching between child tabs

What Changed

• removed the mistaken service_quote_uuid field from the order resource output
• updated purchase-rate application so existing orders attach the newly created purchase rate correctly
• added Order::attachPurchaseRate() to move the order to the new purchase rate and transaction while voiding the prior transaction
• updated order read paths to consistently include purchaseRate.serviceQuote.items
• added distance-unit normalization for m, km, ft, yd, and mi
• added backend support for the parcel calculation method
• expanded algorithm variables to include count-based values such as stops, waypoints, parcels, entities, and base fee
• aligned algorithm validation with the actual runtime expression surface
• fixed the order details route cleanup logic so tab switches no longer trigger full teardown

Verification

• php -l server/src/Http/Controllers/Api/v1/OrderController.php
• php -l server/src/Models/Order.php
• php -l server/src/Models/ServiceRate.php
• php -l server/src/Observers/PurchaseRateObserver.php
• added route regression coverage in tests/unit/routes/operations/orders/index/details-test.js

Notes

• full Ember test execution was not completed in the sandbox because the local runner attempted to bind a restricted port
• style-only lint/prettier cleanup was intentionally left out of scope for this PR