chore(js-ts): Convert store migrations 000-027 to TypeScript

[devin-ai-integration]

Summary

Converts all 28 store migration files (000-027) from JavaScript to TypeScript, plus renames 10 associated test files from .test.js to .test.ts. This is part of the ongoing incremental JS→TS migration effort.

Changes:

• Renamed app/store/migrations/000.js through 027.js → .ts
• Added state: Record<string, unknown> parameter types to all migrate() functions
• Used type assertions for nested state.engine.backgroundState.* property access
• Defined local interfaces where structured data required them (e.g., Token, TransactionMeta, NetworkConfiguration)
• Migrations 023-026 already used @metamask/utils type guards (isObject, hasProperty) — those patterns were preserved
• Renamed 10 test files (019-028.test.js → .test.ts)
• No logic changes — types only

Files changed (53):

• 28 migration files: .js → .ts with type annotations
• 10 test files: .test.js → .test.ts (content unchanged)

Review & Testing Checklist for Human

• Verify that migration type assertions match the expected runtime state shapes (especially migrations 000-018 which use as casts rather than runtime type guards)
• Confirm test files still pass after rename (test content is unchanged, only extension changed)
• Verify app/store/migrations/index.ts imports resolve correctly (extensionless imports should pick up .ts files)

Notes

• Early migrations (000-018) use type assertions (as) for nested state access since they predate the @metamask/utils type guard pattern adopted in later migrations
• Migrations 023+ already had isObject/hasProperty guards which provide runtime type safety
• All CI failures on previous PRs (chore(js-ts): Convert all Redux actions and reducers to TypeScript #611, chore(js-ts): Convert constants and utility files to TypeScript #612) were caused by pre-existing react-native-tcp 404 infrastructure issue, not code changes

Link to Devin session: https://app.devin.ai/sessions/51734166b8b740daa75579e47f5a94be
Requested by: @lukepage-COG

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