feat: show estimated balance changes in confirmation dialog

[wantedsystem]

Summary

• Use Blockaid remote simulation first for estimated balance changes on sign-transaction and MM send, with local fallback when remote simulation is missing, empty, or unsupported.
• Unify the confirmation UI: both flows use the shared EstimatedChanges component, aligned with Tron/Solana.
• Send flow: replace the old inline “You send” asset row with the same estimated-changes section used on sign-tx.
• Sign-tx: seed a local estimate at dialog open, the scan refresher replaces it when Blockaid returns displayable asset rows.
• Send: seed a one-row local fallback from the known send amount/asset, Blockaid can override when simulation returns rows.
• Add Tron-parity loading UX in EstimatedChanges: skeleton while the scan is in flight, plus explicit “not available” / “no changes” states when appropriate.

Notes

• Remote estimated changes win when Blockaid returns non-empty assets. Otherwise the locally seeded fallback stays visible.
• Fees stay in the Network fee row, not in estimated change rows.
• Blockaid validation is unchanged and still drives security alerts only (no change to malicious/warning detection).
• Change-trust still requests validation only — no remote simulation.

[Copilot]

Pull request overview

Adds a local, best-effort Stellar simulation path to surface estimated balance changes on the signTransaction confirmation screen, while keeping Blockaid as validation-only and ensuring the UI hides the section when no usable deltas are available.

Changes:

• Seed the confirmation context with locally-derived estimatedChanges so fund-flow can render immediately, independent of remote scan timing.
• Introduce local simulation endpoint diffing + mapping (SimulationState → TransactionScanEstimatedChanges) and wire it into signTransaction.
• Update the scan refresher to request validation only and to preserve locally-derived estimatedChanges across remote refreshes.

Reviewed changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/snap/src/ui/confirmation/views/ConfirmSignTransaction/ConfirmSignTransaction.tsx	Renders the new estimated-changes section in the sign-transaction confirmation flow.
packages/snap/src/ui/confirmation/controller.tsx	Adds initialScan seeding and gates remote scan scheduling on useSecurityAlerts (validation-only).
packages/snap/src/ui/confirmation/components/index.ts	Exposes the new EstimatedChanges component via the components barrel.
packages/snap/src/ui/confirmation/components/EstimatedChanges/EstimatedChanges.tsx	New UI component to display send/receive asset deltas.
packages/snap/src/ui/confirmation/components/EstimatedChanges/EstimatedChanges.test.tsx	Unit tests for EstimatedChanges rendering/hiding behavior.
packages/snap/src/services/transaction/TransactionSimulator.ts	Adds simulateEndpoints and supports operation-source-only simulation via option flag.
packages/snap/src/services/transaction/TransactionSimulator.test.ts	Tests simulateEndpoints to ensure fee is excluded from estimated-change delta baseline.
packages/snap/src/services/transaction/TransactionService.ts	Adds deriveEstimatedChanges and injects assetMetadataService for SEP-41 metadata mapping.
packages/snap/src/services/transaction/TransactionService.test.ts	Tests local estimated-changes derivation across multiple sign-transaction scenarios.
packages/snap/src/services/transaction/mapSimulationToEstimatedChanges.ts	New mapper converting simulation snapshot deltas into TransactionScanAssetChange[].
packages/snap/src/services/transaction/mapSimulationToEstimatedChanges.test.ts	Unit tests for native + classic mapping and empty/no-signer scenarios.
packages/snap/src/services/transaction/index.ts	Re-exports the new mapper.
packages/snap/src/services/transaction/mocks/transaction.fixtures.ts	Updates TransactionService test fixture construction with assetMetadataService.
packages/snap/src/handlers/keyring/signTransaction.ts	Computes local estimated changes and seeds them into initialScan for the confirmation dialog.
packages/snap/src/handlers/cronjob/refreshConfirmationContext/scanRefresher.ts	Changes refresher behavior to validation-only and preserves local estimatedChanges.
packages/snap/src/handlers/cronjob/refreshConfirmationContext/scanRefresher.test.ts	Updates/adds tests for validation-only options and preservation of local changes.
packages/snap/src/context.ts	Wires assetMetadataService into TransactionService construction.
packages/snap/snap.manifest.json	Updates bundle shasum for the new build output.
packages/site/.env.development	Sets SNAP_ORIGIN for local dev site configuration.

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[Copilot]

Pull request overview

Copilot reviewed 26 out of 27 changed files in this pull request and generated 5 comments.

[stanleyyconsensys]

i think the idea is a not align with our dicussion

• sign txn: always use remote simulation
• chg trust / send : always use local simulation

[stanleyyconsensys]

can we have a enum for out

[stanleyyconsensys]

it looks more clear if we do it via renderOptions
current is

{
      loadPrice: true,
      scanTxn: true,
      validateTxn: true,
 },

to (with some renaming)

// Change trust / confirm send
{
      loadPrice: true,
      securityScanning: true,
      localSimulation: true,
      remoteSimulation: false
 }

// sign txn
{
      loadPrice: true,
      securityScanning: true,
      localSimulation: false,
      remoteSimulation: true
 },

[stanleyyconsensys]

just question why we need to check assetType and asset.type?

[stanleyyconsensys]

this method does not seem useful,
as simulate already give us all the state

[stanleyyconsensys]

sign txn is only using security scan, why we need this?

[stanleyyconsensys]

again, doesnt we said sign txn is using security scanning?

[stanleyyconsensys]

may be we can remove this and let security api to do the work