Five SVG diagrams that anchor the architecture story. Hand-drawn-style, Dracula palette, no external dependencies. Embed in README and doc-site pages as <img> tags. Mirrored into healthlog-docs/src/assets/diagrams/ and healthlog-landing/public/diagrams/ so each surface ships its own copy.

File	Story it tells
`01-data-flow.svg`	Sources (Withings, Apple Health export.zip, iPhone HealthKit, manual, Nightscout) → ingest endpoints → Measurement + MeasurementRollup → reads (rollup probe / live SQL fallback / cache) → surfaces (dashboard, insights, Coach, doctor PDF).
`02-coach-pipeline.svg`	User question → snapshot builder → prompt assembler → provider chain (ChatGPT OAuth / OpenAI / Anthropic / local / admin-shared) → response parser → cited reply with mini-charts.
`03-self-hosting-topology.svg`	Internet → reverse proxy (TLS) → Next.js app (port 3000) ↔ pg-boss worker ↔ Postgres 18, plus GHCR image pull, optional Coolify autodeploy, optional S3 off-host backup.
`04-source-priority.svg`	Three sources for the same metric on the same day → resolver picks one canonical row per (cumulative vs point) ladder. Losing rows stay in the audit trail.
`05-security-model.svg`	Three concentric layers — auth perimeter (passkey + password fallback), session perimeter (HttpOnly cookie + Postgres sessions), encrypted core (AES-256-GCM versioned keys). Side rails: rate limiter, audit log, HMAC tokens, CSP/HSTS, SSRF guard.

Editing

Open in any text editor. Each file is hand-authored SVG ≤ 12 KB; the viewport, the defs block of arrow markers, and the labelled groups are all readable inline. Keep the Dracula palette (#282a36 background, #f8f8f2 text, accents #8be9fd / #ffb86c / #50fa7b / #bd93f9 / #ff79c6 / #ff5555) and the viewBox="0 0 1200 620" constraint so the diagrams stay consistent across the three sites.

After editing, copy the file to the sister repos so all three surfaces ship the updated version.