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/startos/versions/v1.0.0.1.ts

@@ -0,0 +1,34 @@
+import { IMPOSSIBLE, VersionInfo } from '@start9labs/start-sdk'
+
+/**
+ * v1.0.0:1 — initial Proof of Work release.
+ *
+ * Upstream version: 1.0.0
+ * Wrapper rev:      1
+ *
+ * This is a one-shot "seeded cutover" release for users migrating from the
+ * old `workout-log` StartOS package. The Docker image bakes in a snapshot of
+ * the maintainer's live /data volume under /app/seed/data; the entrypoint
+ * copies that snapshot into the new 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 untouched.
+ *
+ * Because StartOS treats `proof-of-work` as a brand new service (different
+ * package id from `workout-log`), the old install stays running until the
+ * operator confirms the cutover and stops it manually. There is no
+ * downgrade path; `down` is IMPOSSIBLE.
+ *
+ * The post-cutover cleanup release (v1.0.0:2) will strip the baked seed and
+ * the seed-copy branch from docker_entrypoint.sh.
+ */
+export const v_1_0_0_1 = VersionInfo.of({
+  version: '1.0.0:1',
+  releaseNotes: {
+    en_US:
+      'Initial Proof of Work release. Replaces the legacy `workout-log` package with multi-user support and a curated exercise library shared across all users on the instance. Bakes a one-time seed of /data into the image and copies it into the new volume only on truly-fresh first boot, so an operator migrating from `workout-log` keeps every workout, exercise, and preference.',
+  },
+  migrations: {
+    up: async () => {},
+    down: IMPOSSIBLE,
+  },
+})