## Context

Current Umami event payloads for hero/feed CTA clicks and summary modal lifecycle events are identifier-heavy (`article_id`) and not directly human-readable in dashboards. Analysts must resolve IDs back to content to understand behavior patterns, which slows ad-hoc exploration and increases reporting friction.

## Goals / Non-Goals

**Goals:**
- Add `article_title` to existing CTA and summary modal analytics payloads.
- Preserve existing event names and current fields for backward compatibility.
- Keep changes scoped to frontend event payload construction.

**Non-Goals:**
- Renaming event names or changing event timing semantics.
- Introducing new analytics providers or backend event pipelines.
- Reworking existing dashboard taxonomy outside payload enrichment.

## Decisions

### Decision 1: Additive payload enrichment only
**Choice:** Add `article_title` as an extra property while retaining `article_id` and existing metadata.

**Rationale:**
- Backward compatible for existing analytics queries.
- Immediate analyst readability improvement without migration burden.

### Decision 2: Use headline string from the in-memory item model
**Choice:** Populate `article_title` from current article object (`item.headline` / `modalItem.headline`).

**Rationale:**
- No extra network calls or state plumbing.
- Data already present where events are emitted.

### Decision 3: Preserve event contracts and dispatch points
**Choice:** Keep event names unchanged (`hero-cta-click`, `summary-modal-open`, `summary-modal-close`).

**Rationale:**
- Avoids dashboard/query breakage.
- Keeps this change low risk and auditable.

## Risks / Trade-offs

- **[Risk] Long titles inflate payload size** -> Mitigation: send raw headline as-is; acceptable for low-volume client events.
- **[Risk] Missing title on edge cases** -> Mitigation: include `article_id` as canonical fallback identifier.
- **[Trade-off] Same event schema differs across historical windows** -> Mitigation: additive field keeps historical queries valid while enabling richer future segmentation.

## Migration Plan

1. Update event emitters in `frontend/index.html` to include `article_title`.
2. Verify emitted payloads in browser devtools/Umami debug path.
3. Update analytics-tagging spec deltas and task checklist.

Rollback:
- Remove `article_title` field additions; existing events remain unchanged.

## Open Questions

- Do analysts also want `article_permalink` included now, or defer to future UX/permalink change?