Enhance validation result/context: Suggestion field, parameters.json, location, docs links

[vhvb1989]

Context

Follow-up from PR #7053 review. Parent tracking issue: #7112

PR Conversations

• Add link to Azure RBAC docs in warning (@tg-msft)
• Improve doc comment for validation functions (@tg-msft)
• Check for .parameters.json too (@tg-msft)
• Pass location to bicep snapshot (@tg-msft)
• Add Suggestion field to PreflightResult (@tg-msft)

What needs to change

1. Suggestion field: Add a Suggestion string field to PreflightResult to mirror the final UI pattern for errors (consistent with ErrorWithSuggestion).
2. Doc comment: Update the validation function doc comment to emphasize graceful failure — checks should not block deployment if a condition is not met or a value is missing.
3. Parameters file: Also check for .parameters.json file when loading bicep parameters.
4. Location: Pass location to bicep snapshot command if known, so it can resolve resourceGroup().location.
5. RBAC docs link: Add a link to Azure RBAC role assignments in the role-assignment warning message to help new users fix the issue.

Files to update

• cli/azd/pkg/infra/provisioning/bicep/local_preflight.go
• cli/azd/pkg/infra/provisioning/bicep/bicep_provider.go

[spboyer]

Telemetry data to help prioritize location validation.

From a Kusto analysis of service.arm.deployment.failed in March 2026 (23 days of data):

InvalidResourceGroupLocation is the inner error code for 350 ARM deployment failures per month (3.9% of all ARM deployment failures). These users wait an average of 5.3 minutes before receiving a region-incompatibility error that could be detected in seconds with a preflight region check.

The failures break down by service host type:

Service Host	Conflict Failures	BadRequest Failures
containerapp	2,453	434
function	827	276
appservice	675	200

Container Apps is the most affected service type for ARM failures overall (31.8% of all ARM failures target containerapp hosts).

A validation rule that checks region support for the required resource types against the Bicep snapshot before deploying would catch these 350 failures/month at preflight time instead of after a multi-minute ARM deployment attempt.

Data source: ddazureclients.kusto.windows.net / DevCli / RawEventsAppRequests, March 1-23, 2026.