Rebrand to Proof of Work; multi-user 0.4 package with curated library sync

Repo cleanup
- Add top-level .gitignore (was missing; node_modules, .next, *.s9pk,
  image.tar, seed/data/*.db, log files, etc.) and a root README.
- Delete legacy start9/0.3.5/ package (StartOS 0.3.5 wrapper, no longer
  the deploy target).
- Delete start9-example-packaging/ (template from another project).
- Delete planning docs (START9_PACKAGING_LOG.md, VERSIONING.md,
  STARTOS_0.4_UPGRADE_PROMPT.md, ICON_FILES_INDEX.md, etc.) — info now
  lives in the deploy guide and code comments.
- Drop the standalone Dockerfile, docker-compose.yml, ICON_*, and dev
  log/build artifacts from the app dir.
- Drop the v0.1.0:18/19/20 version files (they belonged to the legacy
  workout-log package and don't apply to the new id).

Rename + new package
- Rename app dir workout-planner/ -> proof-of-work/.
- Rename StartOS package id workout-log -> proof-of-work; the new id
  makes this a brand new StartOS service (clean cutover from the old
  one rather than in-place upgrade).
- Reset version graph; v1.0.0:1 is the seeded cutover release. The
  Dockerfile bakes a one-time /data snapshot and docker_entrypoint.sh
  copies it into the new volume on truly-fresh first boot only (both
  /data/app.db missing AND /data/.seeded absent).
- Move start9/0.4-migration/ -> start9/0.4/; the old start9/0.4/ stub
  is gone.

Curated exercise library (multi-user-aware)
- proof-of-work/prisma/exercises.seed.json is the canonical library
  shipped to every install (164 exercises today, dumped from the live
  snapshot).
- proof-of-work/scripts/sync-library.cjs (npm run sync-library) refreshes
  the JSON from start9/0.4/seed/data/app.db after refresh_seed.sh.
- proof-of-work/prisma/seed.ts now reads from the JSON instead of a
  hardcoded 52-exercise array; runs at Docker build time to seed the
  fallback DB and on first boot for fresh installs.
- proof-of-work/prisma/ensureExerciseLibrary.cjs runs on every container
  boot (from docker_entrypoint.sh) and INSERT OR IGNOREs every library
  entry for every user, keyed on (userId, name). Library updates flow
  to existing installs on package upgrade; user-custom exercises
  (isCustom=true) and any colliding names are never overwritten;
  removed exercises stay on existing installs (additive-only).

Deploy guide (start9/0.4/DEPLOY_040.md)
- Rewritten end-to-end for the workout-log -> proof-of-work cutover:
  refresh_seed, sync-library, build, sideload, verify, rotate creds,
  stop the old service, then post-cutover cleanup release v1.0.0:2.

start9/0.4/Dockerfile

@@ -0,0 +1,88 @@
+# syntax=docker/dockerfile:1.6
+#
+# Proof of Work (proof-of-work) — StartOS 0.4 package image.
+#
+# Build context: repo root (see manifest.images.main.source.dockerBuild.workdir
+# which is set to '../..' so all COPY paths below are repo-root-relative).
+#
+# This Dockerfile is self-contained: it references only files under
+# `proof-of-work/` (the upstream app) and `start9/0.4/` (this wrapper).
+#
+# Data preservation (v1.0.0:1 — initial seeded cutover):
+#   - This image bakes a one-time snapshot of the maintainer's live /data
+#     volume under /app/seed/data so the cutover from the legacy `workout-log`
+#     package preserves every workout, exercise, and preference.
+#   - docker_entrypoint.sh copies the seed into the StartOS-managed /data
+#     volume only on a truly-fresh first boot (both /data/app.db missing AND
+#     /data/.seeded absent). Every subsequent boot leaves /data alone.
+#   - v1.0.0:2 will strip the seed copy from the image and the seed-copy
+#     branch from the entrypoint once the cutover is verified in production.
+#   - A tiny empty-schema fallback DB is also COPYed from the builder stage
+#     (at /app/prisma/data/app.db) as a safety net for fresh sideloads on a
+#     brand-new host with no existing /data and no baked seed.
+
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+RUN apk add --no-cache openssl
+
+COPY proof-of-work/package.json proof-of-work/package-lock.json ./
+RUN npm ci
+
+COPY proof-of-work/ ./
+RUN npx prisma generate
+
+# Build a fallback empty-but-schema-correct DB. Used by docker_entrypoint.sh
+# only when /data has no app.db AND no baked seed is available (i.e. after
+# v1.0.0:2 strips the seed). Seeded with the curated exercise library via
+# `npm run db:seed`, so a brand-new install still gets the full library.
+RUN mkdir -p /tmp-seed \
+ && DATABASE_URL=file:/tmp-seed/app.db npx prisma db push --skip-generate \
+ && DATABASE_URL=file:/tmp-seed/app.db npm run db:seed
+
+RUN npm run build
+
+FROM node:20-alpine AS runner
+
+WORKDIR /app
+
+RUN apk add --no-cache dumb-init curl openssl sqlite \
+ && addgroup -S nodejs -g 1001 \
+ && adduser -S nextjs -u 1001 -G nodejs
+
+ENV NODE_ENV=production \
+    HOSTNAME=0.0.0.0 \
+    PORT=3000 \
+    WORKOUT_DATA_DIR=/data \
+    WORKOUT_DB_PATH=/data/app.db \
+    WORKOUT_FALLBACK_SEED_DB_PATH=/app/prisma/data/app.db \
+    WORKOUT_BAKED_SEED_DB_PATH=/app/seed/data/app.db \
+    WORKOUT_LIBRARY_JSON_PATH=/app/prisma/exercises.seed.json
+
+# Next.js standalone runtime bundle
+COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
+COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
+COPY --from=builder --chown=nextjs:nodejs /app/public ./public
+COPY --from=builder --chown=nextjs:nodejs /app/prisma ./prisma
+
+# Empty-schema fallback DB (used only when no baked seed is available on a
+# brand-new sideload).
+COPY --from=builder --chown=nextjs:nodejs /tmp-seed/app.db /app/prisma/data/app.db
+
+# Baked one-time cutover seed: the maintainer's live /data snapshot pulled
+# off the running `workout-log` host via refresh_seed.sh. Copied into /data
+# only on truly-fresh first boot. Removed in v1.0.0:2.
+COPY --chown=nextjs:nodejs start9/0.4/seed/data /app/seed/data
+
+# Container entrypoint and diagnostic healthcheck
+COPY start9/0.4/docker_entrypoint.sh /usr/local/bin/docker_entrypoint.sh
+COPY start9/0.4/healthcheck.sh /usr/local/bin/healthcheck.sh
+
+RUN chmod +x /usr/local/bin/docker_entrypoint.sh /usr/local/bin/healthcheck.sh \
+ && mkdir -p /data \
+ && chown -R nextjs:nodejs /app /data
+
+EXPOSE 3000
+
+ENTRYPOINT ["dumb-init", "--", "/usr/local/bin/docker_entrypoint.sh"]