Add SOP activity bar chart to workflow dashboard

[vepretski]

Motivation

• Provide a quick visual summary of SOP activity on the dashboard so operators can see which SOPs have been executed most often and surface that at the top of the page.

Description

• Modified src/workflow_product_module.py to add get_sop_run_totals() which aggregates run counts by SOP id.
• Updated dashboard_html() to render a new "SOP Activity (Bar Chart)" card at the top of the dashboard and compute relative bar widths from the run totals.
• Added lightweight inline CSS for the bar chart, a per-SOP row layout, and an empty-state message when no runs exist.

Testing

• Ran pytest -q tests/test_workflow_product_module.py and all tests passed (5 passed).
• Launched the module with python -m src.workflow_product_module and verified a smoke GET of /dashboard via curl -sSf http://localhost:8080/dashboard returned the updated HTML including the new chart card.

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Codex Task