Propose social MVP: public-content-visibility + demo-activity-bot

Two stacked OpenSpec change proposals for a demoable social layer,
with scope deliberately minimal ("enough to send a URL and have it
open to real-looking content without signup"):

1. public-content-visibility
   - Adds visibility enum {private, unlisted, public} on routes +
     activities, defaulting to private for every existing row.
   - Detail pages (/routes/:id, /activities/:id) become accessible to
     logged-out visitors when content is public or unlisted; private
     → 404 (not 403) to avoid existence leaks.
   - Broadens /users/:username into a public profile listing only
     public routes + activities; 404s when there's no public content
     to prevent account enumeration.
   - Open Graph / Twitter Card meta on public detail + profile pages.
   - Visibility selector in the owner's edit flow.
   - Out of scope: follow/follower, cross-user feed, reactions,
     federation.

2. demo-activity-bot  (depends on #1)
   - A single bot user, Bruno the trail dog, seeded on worker startup
     when DEMO_BOT_ENABLED=true. Reserved username, sentinel email,
     no credentials.
   - pg-boss recurring job fires every 90 min, decides-to-walk with
     p=0.12 during 07:00-21:00 local, yielding ~2-3 walks/day at
     organic times.
   - Each walk: random start + end within inner-Berlin bbox, trekking
     only (dogs don't ride bikes), 2-12 km crow. BRouter plans the
     route; the route GPX is also attached as the activity's trace.
   - Everything inserted with visibility=public, synthetic=true.
   - Daily prune deletes synthetic rows > DEMO_BOT_RETENTION_DAYS old
     (default 14). Hard cap of 40 items/14d protects against runaway
     growth.
   - Small "🐕 demo account" badge on /users/bruno for honesty.

Both changes are artifacts only — no code lands with this PR. Apply
in order after merge: public-content-visibility first, then
demo-activity-bot.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

openspec/changes/demo-activity-bot/tasks.md

@@ -0,0 +1,72 @@
+## 1. Schema
+
+- [ ] 1.1 Add `synthetic boolean NOT NULL DEFAULT false` to `journal.routes` in `packages/db/src/schema/journal.ts`
+- [ ] 1.2 Add the same column to `journal.activities`
+- [ ] 1.3 Verify existing CRUD helpers (`createRoute`, `updateRoute`, `createActivity`, `listRoutes`, `listActivities`) compile and ignore the new column for default callers
+
+## 2. Bruno bootstrap
+
+- [ ] 2.1 Reserved username: `bruno`. Sentinel email: `bruno@<DOMAIN>`. Display name: `Bruno`. Bio: a short whimsical line (finalise exact wording during apply — e.g. "Professional park inspector. Currently accepting tennis balls.").
+- [ ] 2.2 Add an `ensureDemoUser()` helper in `apps/journal/app/lib/demo-bot.server.ts` that inserts the `bruno` row only if missing (idempotent via `ON CONFLICT DO NOTHING` on `username`), with `terms_accepted_at` and `terms_version` populated.
+- [ ] 2.3 Call `ensureDemoUser()` from the worker startup sequence when `DEMO_BOT_ENABLED === "true"`.
+- [ ] 2.4 Confirm Bruno has no credentials row; the passkey and magic-link login paths both fail for his email (no mailbox exists for `bruno@<DOMAIN>`).
+
+## 3. Region + generation helpers
+
+- [ ] 3.1 Add `loadRegion()` that reads `DEMO_BOT_REGION` JSON (with `bbox: [w,s,e,n]`) and falls back to the inner-Berlin default `[13.25, 52.45, 13.55, 52.60]`
+- [ ] 3.2 Add `pickEndpoints(bbox)` — random start + end, 2–12 km crow distance apart (dog-walk scale)
+- [ ] 3.3 Profile is fixed to `trekking` (Bruno doesn't ride bikes); no `pickProfile()` needed for v1
+- [ ] 3.4 Add `templateName(startedAt)` + `templateDescription()` — EN + DE Bruno-voiced copy, mixing serious-audit flavour ("Grunewald north-loop patrol") and comic ("Bruno found three sticks today 🐕"); 10–15 entries in each pool, picked deterministically from the day + started-at to avoid same-day repeats
+
+## 4. BRouter client for the bot
+
+- [ ] 4.1 Reuse the existing `computeRoute` helper where possible; otherwise add a minimal `brouter-client.server.ts` that POSTs to `process.env.BROUTER_URL` and returns parsed GPX + stats
+- [ ] 4.2 On no-route / 5xx / timeout, return a typed "no route" error — the job handles it, does not throw out of the worker
+
+## 5. Generation job
+
+- [ ] 5.1 Register a pg-boss recurring job `demo-bot:generate` to fire every 90 minutes, singleton mode
+- [ ] 5.2 Handler: skip immediately if `DEMO_BOT_ENABLED !== "true"`
+- [ ] 5.3 Decide-to-walk gate: compute local hour; if outside 07:00–21:00 → skip. Otherwise roll a Bernoulli with p=0.12 and skip if it doesn't fire. Expected output: ~2–3 walks/day
+- [ ] 5.4 Hard cap: `SELECT count(*) FROM routes WHERE synthetic AND created_at > now() - interval '14 days'`; skip if >= 40
+- [ ] 5.5 Pick region + endpoints (profile is fixed to `trekking`); call BRouter; on failure log and return
+- [ ] 5.6 Insert route with `visibility='public'`, `synthetic=true`, owner = Bruno; insert linked activity with derived `started_at` = now, `duration` = distance ÷ ~4.5 km/h ± jitter, stats, and the same GPX
+
+## 6. Initial backfill
+
+- [ ] 6.1 At the top of the generation handler, check if `count(synthetic routes) == 0`; if so, loop up to 5 times running the full generation body sequentially (each call independent — if one fails, keep going)
+- [ ] 6.2 After the backfill path, fall through to the normal single-item generation
+
+## 7. Retention job
+
+- [ ] 7.1 Register a pg-boss recurring job `demo-bot:prune` with a cron like `15 3 * * *` (daily at 03:15 UTC), singleton
+- [ ] 7.2 Handler: skip if `DEMO_BOT_ENABLED !== "true"`
+- [ ] 7.3 Read `DEMO_BOT_RETENTION_DAYS` with default 14
+- [ ] 7.4 `DELETE FROM journal.activities WHERE synthetic AND created_at < now() - interval ?`; same for routes
+- [ ] 7.5 Log the count removed for observability
+
+## 8. Ops + env surface
+
+- [ ] 8.1 Document `DEMO_BOT_ENABLED`, `DEMO_BOT_RETENTION_DAYS`, `DEMO_BOT_REGION` in `infrastructure/secrets.app.env`'s commented template (do not enable in any environment file except prod)
+- [ ] 8.2 Set `DEMO_BOT_ENABLED=true` only in prod
+- [ ] 8.3 Expose counts via a Prometheus gauge (e.g. `demo_bot_synthetic_routes_total`, `demo_bot_synthetic_activities_total`) and reuse the existing `brouter_request_duration_seconds` histogram for the bot's BRouter calls — no new metric plumbing needed
+
+## 9. UX tweaks
+
+- [ ] 9.1 "🐕 demo account" badge on `/users/bruno` so honest readers can tell at a glance; gate on `user.username === 'bruno'`
+- [ ] 9.2 i18n: `demo.badge` key in EN + DE (e.g. "Demo account" / "Demo-Konto")
+
+## 10. Tests
+
+- [ ] 10.1 Unit: `ensureDemoUser` is idempotent; second call is a no-op and does not duplicate
+- [ ] 10.2 Unit: `pickEndpoints` stays within bbox; distance bands match profile
+- [ ] 10.3 Unit: `templateName` / `templateDescription` return non-empty strings in both locales
+- [ ] 10.4 Integration (tests DB): the generation handler inserts one route + one activity with `synthetic=true, visibility='public'` when enabled, and inserts nothing when disabled
+- [ ] 10.5 Integration: the prune handler deletes only `synthetic=true` rows past the window; real rows are untouched
+
+## 11. Rollout
+
+- [ ] 11.1 Merge schema + code; deploy — the bot stays disabled everywhere because no env flag is set
+- [ ] 11.2 Flip `DEMO_BOT_ENABLED=true` on prod via the SOPS env file + redeploy
+- [ ] 11.3 On next worker start: verify `ensureDemoUser` created the `demo` user, the backfill produced 3–5 items, and `/users/demo` renders them publicly
+- [ ] 11.4 After 24 h: verify cadence looks right and the prune job ran without deleting anything yet