feat(transaction-pay-controller): add route-based strategy resolution

[pedronfigueiredo]

Explanation

This change moves the generic confirmations_pay strategy-order routing logic into @metamask/transaction-pay-controller so clients no longer need to own the raw feature-flag parsing and ordered strategy resolution themselves. The controller now supports an optional getStrategyRouteContext callback for client-specific route derivation, while the package exposes getStrategyOrderForRouteFromFeatureFlags for non-controller consumers that still need to answer route-based flag questions from the same generic implementation.

This keeps the controller flexible for custom client overrides while standardizing the shared transactionType / chainId / tokenAddress routing policy in one place. As part of that, the transaction-pay feature-flag utilities now apply RemoteFeatureFlagController.localOverrides before resolving confirmations_pay, which matches how MetaMask Mobile already consumes those flags.

References

• Related to refactor: split mm pay ui type cleanup into follow-up pr metamask-mobile#27867
• Consumer follow-up branch: pnf/plan-provider-fallback-rollout

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

---

Note

Medium Risk
Changes how TransactionPayController selects pay strategies by introducing route-context-based feature-flag resolution and by applying localOverrides before remote flags, which can alter runtime strategy ordering for transactions and quote refreshes.

Overview
Adds route-based pay strategy resolution to TransactionPayController via an optional getStrategyRouteContext callback; when no explicit getStrategy/getStrategies is provided (or they return no valid strategies), the controller now derives an ordered strategy list using transactionType/chainId/tokenAddress routing overrides before falling back to the global strategyOrder.

Introduces getStrategyOrderForRoute/getStrategyOrderForRouteFromFeatureFlags helpers that normalize and validate routing configs (case-insensitive hex matching, dedupe/filter invalid entries, and drop disabled strategies), and updates feature-flag parsing to apply RemoteFeatureFlagController.localOverrides over remoteFeatureFlags. Public exports and tests are updated accordingly.

^{Written by Cursor Bugbot for commit 85b9724. This will update automatically on new commits. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

[jpuri]

We can probably avoid adding logic to this file and restrict it to code to fetch flag values.

[pedronfigueiredo]

Agree. I will move the route-resolution helper out of feature-flags.ts and keep this file limited to fetching and normalizing raw confirmations_pay values.