✨ Foundations: Trends API, DST-safe durations, SSR Trends page

[ebigunso]

Summary

This PR delivers the foundational backend and UI pieces for Sprint 3. It introduces DST-safe duration semantics, a SQL view for daily sleep with pre-computed duration, on-demand Trends JSON endpoints, and a minimal SSR Trends page wired with Chart.js.

Key changes

• Duration semantics (DST-safe, wake-date)

  • Server-side duration computation using chrono-tz in Rust with wake-date semantics; supports cross-midnight sessions and DST gaps/overlaps.
  • Persisted as sleep_metrics.duration_min for consistent downstream use.
  • Removed the previous wake-after-bed restriction and 2–14h duration guard; any positive duration is accepted (per product guidance).
  • Files: sleep-api/src/time.rs, sleep-api/src/handlers.rs (compute & persist).

• DB migrations & view

  • 0002_add_duration_min.sql: adds sleep_metrics.duration_min; partial unique index for a daily exercise sentinel.
  • 0003_views.sql: v_daily_sleep view exposing wake_date, bed_time, wake_time, latency_min, awakenings, quality, duration_min.

• Trends endpoints (on-demand JSON)

  • GET /api/trends/sleep-bars?from=&to=
    • Returns [{date, bed_time, wake_time, quality?, duration_min?}] based on v_daily_sleep.
  • GET /api/trends/summary?from=&to=&bucket=day|week
    • Aggregates: duration (avg/min/max), quality (avg), latency (median in Rust). Week bucket uses ISO (YYYY-Www).
  • Implementation: sleep-api/src/trends.rs

• SSR Trends page

  • GET /trends renders an Askama template with date range + bucket controls and Chart.js charts for Sleep Bars (duration proxy), Duration avg, Quality avg, Latency median.
  • Files: sleep-api/src/views.rs, sleep-api/templates/trends.html, route in src/app.rs.

• OpenAPI

  • openapi.yaml updated with trends endpoints and response shapes.

• Dependency updates & routing

  • axum 0.8.4, sqlx 0.8.6, askama 0.14 (+ askama_web), tower-http 0.6, axum-extra 0.10.
  • Migrated route patterns to Axum 0.8 syntax (/{id}).

• Tests & quality

  • All existing tests pass.
  • Added tests/trends_bars.rs: validates /api/trends/sleep-bars contract.
  • Clippy cleanup: removed unused DomainError variant and unused cookie-key util; build is clean.

How to run locally

• Build & Test: cargo build, cargo test
• Run (Windows cmd example): set DATABASE_URL=sqlite://./sleep.db && cargo run
• Verify:
  • Health: http://localhost:8080/health
  • Trends page: http://localhost:8080/trends
  • JSON: http://localhost:8080/api/trends/sleep-bars?from=2025-06-01&to=2025-06-30

Notes & next steps

• Auth + session + CSRF (single-user) not included in this PR; will secure /ui/* and mutating routes next.
• Dashboard + HTMX modals (Quick Log, Create/Edit/Delete) + Day view are incoming in subsequent PR(s), along with mobile/a11y polish and security headers.

This sets the groundwork for the Sprint 3 UI flows and trends exploration while keeping time semantics correct across DST.

[Copilot]

Pull Request Overview

This PR implements foundational backend and UI components for Sprint 3, introducing DST-safe duration calculations, Trends API endpoints, and a server-side rendered Trends page with Chart.js visualizations.

• Adds DST-safe duration computation using chrono-tz with wake-date semantics
• Implements Trends API endpoints for sleep data visualization and aggregated metrics
• Creates SSR Trends page with Chart.js charts for sleep analysis

Reviewed Changes

Copilot reviewed 17 out of 18 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
sleep-api/src/time.rs	DST-safe duration computation with timezone handling
sleep-api/src/trends.rs	Trends API endpoints for sleep bars and summary data
sleep-api/templates/trends.html	SSR template with Chart.js charts and date controls
sleep-api/src/views.rs	Askama template struct for trends page
migrations/0002_add_duration_min.sql	Database migration adding duration_min column
migrations/0003_views.sql	SQL view for daily sleep data
sleep-api/tests/trends_bars.rs	Integration test for sleep-bars endpoint
sleep-api/src/handlers.rs	Updated to compute and persist duration
sleep-api/src/repository.rs	Modified to accept and store duration_min
sleep-api/src/app.rs	Added trends routes and template rendering
sleep-api/Cargo.toml	Updated dependencies for new functionality