feat: display gateway target sync status after deploy

[aidandaly24]

Description

After deploying gateways, users had no feedback on whether their targets successfully connected to external MCP servers. The deploy output showed gateway URLs but nothing about target status — users had to go to the console to check.

This PR queries the ListGatewayTargets API after deploy completes and displays the sync status of each target:

Gateway Targets:
 my-mcp-server: ✓ synced
 another-target: ⟳ syncing...

Status mappings:

• READY → ✓ synced
• SYNCHRONIZING → ⟳ syncing...
• SYNCHRONIZE_UNSUCCESSFUL → ⚠ sync failed
• CREATING → ⟳ creating...
• FAILED → ✗ failed

Integrated into both the CLI deploy path (deploy/actions.ts) and the TUI deploy path. The TUI uses proper React state management — statuses are stored in targetStatuses state and rendered as components in DeployScreen, not hacked through the logger.

API errors are non-blocking — if the status query fails (permissions, network, etc.), the deploy still succeeds and the status display is simply skipped.

Related Issue

Part of the MCP Gateway Phase 1 integration (gateway-integration branch). Task 11b.

Type of Change

• New feature

Testing

How have you tested the change?

• I ran npm run test:unit and npm run test:integ
• I ran npm run typecheck
• I ran npm run lint
• If I modified src/assets/, I ran npm run test:update-snapshots and committed the updated snapshots

9 new tests covering:

• ListGatewayTargets returns multiple targets with various statuses
• API error returns empty array (non-blocking)
• Empty gateway (no targets)
• Undefined items in response
• formatTargetStatus for all known status values and unknown fallback

Checklist

• I have read the CONTRIBUTING document
• I have added any necessary tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature, or no new docs are needed
• My changes generate no new warnings
• Any dependent changes have been merged and published