SAP-2475: Add EC2 IAM drift guard and stage HTTP placeholder support

[padili-metrostar]

Pull Request

🔍 Description

Implements SAP-2475 reliability improvements for Quartz AWS/tofu workflows.

• Added early EC2 IAM state-drift/orphan detection before apply (role/profile present in AWS but absent in state)
• Added clear remediation guidance in error output for import vs cleanup paths
• Added helper APIs for IAM role/profile existence checks in provider layer
• Added stage HTTP check placeholder support and test coverage
• Added/updated unit tests for drift error behavior and provider/stage logic

Related Jira: https://metrostarsystems.atlassian.net/browse/SAP-2475

📋 Checklist

• I have tested this PR locally.
• I have added/updated unit tests where applicable.
• This PR adheres to the conventional commits standard.
• I have run golangci-lint run and resolved all issues.
• I have verified this PR does not expose any secrets or sensitive information.
• I have updated documentation (README, CLI help text, etc.) if needed.

📦 Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update
• Test or CI/CD improvement
• Refactor or code cleanup
• Other (describe):

🧪 How to Test

1. Run go test ./...
2. Run golangci-lint run
3. Run mise run test-ci

📸 Screenshots / Output

• go test ./... passes
• golangci-lint run passes
• mise run test-ci passes

🧑‍⚖️ Reviewer Notes

Please focus review on the new state-drift guard path in internal/cmd/tofu.go and provider IAM existence probes.

[codecov]

Codecov Report

❌ Patch coverage is 47.52475% with 53 lines in your changes missing coverage. Please review.
✅ Project coverage is 57.60%. Comparing base (58b6f29) to head (e7a5abf).

Files with missing lines	Patch %	Lines
internal/cmd/tofu.go	50.84%	28 Missing and 1 partial ⚠️
internal/provider/aws.go	0.00%	24 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #66      +/-   ##
==========================================
- Coverage   57.72%   57.60%   -0.12%     
==========================================
  Files          68       68              
  Lines        7422     7519      +97     
==========================================
+ Hits         4284     4331      +47     
- Misses       2688     2738      +50     
  Partials      450      450              

Files with missing lines	Coverage Δ
internal/provider/aws_sdk.go	100.00% <ø> (ø)
internal/stages/http_check.go	87.61% <100.00%> (+1.75%)	⬆️
internal/provider/aws.go	70.70% <0.00%> (-12.76%)	⬇️
internal/cmd/tofu.go	52.95% <50.84%> (-0.20%)	⬇️

... and 2 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[marshyski]

LGTM

[github-actions]

🎉 This PR is included in version 1.2.0 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀