Feature: Personal Skill Usage Analytics in Daily Dashboard

[Q00]

Summary

Add a personal skill usage breakdown to each user's Daily Dashboard (/daily), so individuals can see which skills (slash commands) they invoke most frequently.

Motivation

The current Daily Dashboard shows sessions, cost, and token usage — but there's no visibility into which skills a user relies on most. Understanding personal skill patterns helps users:

• Discover underutilized skills that could improve their workflow
• Track adoption of newly learned skills over time
• Identify habits and optimize their Claude Code usage

Current State

• /daily page displays: 30-day sessions, cost, input/output tokens, cost chart, token chart
• Skill analytics exist only in the admin panel (/admin/analytics) via getTeamTopSkills, getSkillUsageTrend, etc.
• No per-user skill breakdown is surfaced anywhere in the non-admin dashboard

Proposed Solution

1. New API endpoint: GET /api/my/skills — returns the authenticated user's skill invocation counts, grouped by skill name, for a configurable period (7d / 30d)
2. Daily Dashboard widget: A new card/section on /daily showing:
   • Top 5 skills (bar chart or ranked list with invocation counts)
   • Skill usage trend (sparkline or small area chart showing daily skill invocations)
   • New skills this week (highlight skills used for the first time)
3. Query ClickHouse ai_prompts table filtered by user_id and aggregated by skill/command name

Design Considerations

• Keep it lightweight — this is a personal glance view, not a deep analytics page
• Reuse existing prompt-analytics query patterns from the admin skills API
• Consider caching to avoid expensive per-user ClickHouse queries on every page load

Acceptance Criteria

• Each user can see their top invoked skills on the Daily Dashboard
• Skill usage trend is visible over a selectable time range
• No admin privileges required — scoped to the authenticated user's own data