Fix medium-severity spec drift across 17 specs

- authentication-methods: document completeAuth mode param ("redirect"|"json");
  clarify add-passkey nudge (no dismiss mechanism, disappears on passkey add)
- journal-auth: session maxAge is 30 days; terms allow-list uses /legal/ prefix
  matching (broader than fixed list of paths)
- session-notes: mark awareness isolation and UndoManager isolation as not yet
  implemented (shared instances in current code)
- activity-feed: add fan-out scenario for visibility change to public
- explore: note that ?perPage is not yet implemented (hardcoded page size)
- multi-day-routes: add per-day GPX track split scenario (splitByDays option);
  document overnight vs isDayBreak naming gap
- osm-poi-overlays: debounce is 800ms + 2000ms min interval (not 500ms);
  retry is not automatic (fires on next viewport change)
- brouter-integration: rate limit corrected to 300/hour; add segment-cache
  requirement (client caches per-pair segments)
- wahoo-route-push: OAuth state shape uses camelCase (returnTo, pushAfter
  object) not snake_case with push_after boolean
- komoot-import: document noop adapter / ConnectedServiceManager bypass;
  note four Komoot-specific routes that bypass the generic OAuth framework
- background-jobs: exponential backoff not wired (retryLimit only); add SIGINT
- connected-services: add revoked status; name ConnectionNotActiveError
- infrastructure: add INTEGRATION_SECRET and SENTRY_DSN to env var lists;
  split secret decryption scenario by workflow (cd-apps vs cd-infra)
- secret-management: correct CD decryption — cd-apps only decrypts app.env;
  cd-infra decrypts both
- transactional-emails: welcome email is async (pg-boss job); magic-link email
  includes 6-digit numeric code
- journal-route-detail: websites are https: links (not mailto:); opening_hours
  is also displayed
- local-dev-environment: add mobile app (Expo) dev commands

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

openspec/specs/explore/spec.md

@@ -95,6 +95,8 @@ The directory SHALL paginate via `?page=N` (1-indexed) and `?perPage=K` query pa
 - **WHEN** a visitor loads `/explore?perPage=10000` or `/explore?perPage=0`
 - **THEN** the loader clamps `perPage` to `[1, 100]` and renders normally — no 400 response
 
+Note: the `?perPage` parameter is not yet implemented. The current loader uses a hardcoded page size (20). The `?page` parameter is supported. `perPage` support is aspirational.
+
 #### Scenario: Page beyond the last
 - **WHEN** a visitor loads `/explore?page=N` where N is past the last populated page
 - **THEN** the response renders the empty list and a "Previous page" link; no 404