docs: workflow-architecture.md needs updates for recent changes

[aRustyDev]

Problem

docs/src/ci/workflow-architecture.md doesn't reflect recent workflow changes.

Issues Found

1. Missing Auto-Merge Workflow

No mention of auto-merge-integration.yaml which handles:

• Trust-based auto-merge for integration PRs
• Dependabot trust path
• CODEOWNERS verification
• Commit signature verification

2. Missing repository_dispatch Trigger

W6 (release-atomic-chart.yaml) now supports repository_dispatch trigger for secure manual releases. This isn't documented.

3. Missing ci/dependencies Branch

W2 now has a process-dependencies job that routes dependabot workflow updates to a ci/dependencies atomic branch. Not documented.

4. Branch Naming Convention Incomplete

Doc mentions charts/<chart> and integration/<chart> patterns but doesn't mention ci/dependencies.

5. Workflow File Names May Be Outdated

Need to verify the workflow file names match what's actually in .github/workflows/.

Recommended Changes

1. Add section on auto-merge workflow
2. Document repository_dispatch trigger for W6
3. Add ci/dependencies branch to branch naming section
4. Update any stale workflow file references
5. Add diagram showing auto-merge integration

Related

• Part of documentation refresh for chart release workflows