Consume CC 'skill_activated' OTel invocation_trigger for marketplace analytics

[itsdestin]

Surfaced by /release v1.2.2 → next review (review-cc-changes agent — future-work item).

CC v2.1.126 made the `claude_code.skill_activated` OpenTelemetry event fire for user-typed slash commands (previously only proactive activations) and added a new `invocation_trigger` attribute with values:

• `"user-slash"` — user typed the slash command
• `"claude-proactive"` — Claude invoked the skill on its own
• `"nested-skill"` — invoked from inside another skill

YouCoded's analytics pipeline (`wecoded-marketplace/worker/`) currently has no skill-invocation telemetry. If YouCoded wired up an OTel collector — even a local-only one writing to the analytics endpoint — this would let the marketplace tell which skills get used proactively vs. need user prompting, useful for ranking and discovery.

Considerations

• Privacy review required — currently no skill-level telemetry is sent. This would change the data envelope; the existing privacy guarantees in `AboutPopup.tsx` and the landing-page FAQ would need updating.
• Storage — Analytics Engine has the right shape; AE blob order is the contract (see PITFALLS "Analytics" section).
• Effort — medium. Need a local OTel collector that ships to the Worker, plus the Worker needs a new event type and corresponding admin SQL queries.

Quoted CHANGELOG entry

v2.1.126: `claude_code.skill_activated` OpenTelemetry event now fires for user-typed slash commands and carries a new `invocation_trigger` attribute (`"user-slash"`, `"claude-proactive"`, or `"nested-skill"`).