cherry-pick: fix: Update STX Banner Alert, include chainSupportsSmartTransactions

[httpJunkie]

Cherry-pick of #29911
Related Issue (#29869)

• Added selectors for chain support and preference enabled
• Updated alertConditions to include chain support and preference enabled checks

The banner will now only show if the chain supports smart transactions and they are enabled in preferences.

Description

1. Reason for change: The Smart Transactions banner was showing incorrectly for users who had STX enabled before migration. The banner should only show for users when STX is newly enabled by the migration.

2. Improvement/solution: Modified migration script to only set smartTransactionsMigrationApplied when STX is newly enabled during migration, rather than setting it for all migrated users. This ensures the banner's display logic correctly identifies users who need to see the STX announcement.

Related issues

Fixes: #29869

Manual testing steps

1. Install older version of MetaMask with STX enabled
2. Upgrade to version with these changes
3. Verify banner does not show for pre-enabled STX users
4. Install older version with STX disabled
5. Upgrade to version with these changes
6. Verify banner shows when migration enables STX

Screenshots/Recordings

Load old version 12.5.0 and turn STX OFF, go through migration and ensure that:

• STX is now ON
• Banner Alert shows only on STX supported chains

stx-off-to-on.mp4

Load old version 12.5.0 and turn STX ON, go through migration and ensure that:

• STX is still ON
• Banner Alert does not show

stx-on-to-on.mp4

Before

Banner shows for all users after migration, even those who had STX previously enabled.

After

Banner only shows for users where migration newly enabled STX.

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards
• I've completed the PR template to the best of my ability
• I've included tests:
  • Updated migration tests to verify new behavior
  • Updated component tests to work with new migration logic
  • Fixed existing integration tests
• I've documented my code using JSDoc format where applicable
• I've applied the right labels on the PR

Pre-merge reviewer checklist

• I've manually tested the PR
• I confirm that this PR addresses all acceptance criteria and includes necessary testing evidence

---

Description

Related issues

Fixes:

Manual testing steps

1. Go to this page...

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[metamaskbot]

Builds ready [3fca9ef]

• builds: chrome, firefox
• builds (flask): chrome, firefox
• builds (MMI): chrome
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7
  • common: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
  • ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
  • content-script: 0
  • offscreen: 0

Page Load Metrics (1783 ± 71 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1568	2069	1779	150	72
		domContentLoaded	1553	2046	1743	140	67
		load	1570	2074	1783	147	71
		domInteractive	24	123	43	26	12
		backgroundConnect	6	93	33	22	11
		firstReactRender	16	82	29	20	10
		getState	5	150	34	35	17
		initialActions	0	1	0	0	0
		loadScripts	1129	1593	1294	122	59
		setupStore	7	57	16	17	8
		uiStartup	1746	2548	2051	197	94