[comp log_backend] Component DFA creation

## What

Create the Component DFA (`wp__sw_component_dfa`) for the component log_backend. The DFA analyzes dependent failures at component level, including interactions between safety-related and non-safety-related sub-elements with different ASIL.

## How

**Process step:** [wf__analyse_comparch](https://eclipse-score.github.io/process_description/main/process_areas/safety_analysis/safety_analysis_workflow.html#wf__analyse_comparch)

## Definition of Done

All criteria of the [Safety Analysis Checklist](https://eclipse-score.github.io/process_description/main/process_areas/safety_analysis/guidance/safety_analysis_checklist.html) are met.

## Template & Folder Structure

- **Template:** [Component DFA Template](https://eclipse-score.github.io/module_template/main/score/component_example/docs/safety_analysis/dfa.html)
- **Folder:** `score//docs/safety_analysis/` – see [Module Folder Structure](https://eclipse-score.github.io/module_template/main/index.html#module-layout)

*Please apply the linked template and folder structure to ensure consistency across the S-CORE project.*

Read the linked analyse_comparch process step and Safety Analysis Checklist first, then use the Component DFA Template as the structure for the artifact. Create the DFA under score//docs/safety_analysis/ for log_backend, covering dependent failures across safety-related and non-safety-related sub-elements with different ASIL. Done means every checklist criterion is met and the folder structure is consistent with the module layout.

Written by the indexing model from the issue text.