Fix all OpenSpec validation failures (36/36 passing)

- Add ## Purpose sections and convert delta headers to ## Requirements
  on all 25 specs
- Add SHALL keywords to requirements missing them (gpx-import,
  planner-session, planner-journal-handoff)
- Convert prose GPX format section to proper scenarios (no-go-areas)
- Create specs/ delta files for 7 changes that were missing them
  (activity-photos, local-dev-stack, multi-day-routes, route-discovery,
  route-sharing, visual-redesign, waypoint-notes)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

openspec/changes/activity-photos/specs/activity-photos/spec.md

@@ -0,0 +1,52 @@
+## ADDED Requirements
+
+### Requirement: Photo upload via presigned URLs
+Users SHALL be able to upload photos to an activity using presigned PUT URLs, with client-side image processing before upload.
+
+#### Scenario: Upload photo
+- **WHEN** a user selects a photo on the activity detail page
+- **THEN** the client resizes the image (max 2048px long edge), strips EXIF data, converts to WebP
+- **AND** requests a presigned PUT URL from `POST /api/activities/:id/photos`
+- **AND** uploads directly to Garage (S3-compatible storage)
+- **AND** confirms the upload via `PATCH /api/activities/:id/photos/:photoId`
+
+#### Scenario: Size limit enforced
+- **WHEN** a processed photo exceeds 5 MB
+- **THEN** the presigned URL rejects the upload via content-length condition
+
+#### Scenario: Per-activity photo limit
+- **WHEN** an activity already has 20 photos
+- **THEN** the server rejects new presigned URL requests
+
+### Requirement: Photo gallery display
+The activity detail page SHALL display uploaded photos in a responsive grid with lightbox viewing.
+
+#### Scenario: Gallery grid
+- **WHEN** a user views an activity with photos
+- **THEN** photos are displayed in a responsive grid (1 column mobile, 2 tablet, 3 desktop) with lazy loading
+
+#### Scenario: Lightbox view
+- **WHEN** a user clicks a photo in the gallery
+- **THEN** a full-size lightbox overlay opens with left/right navigation and close on escape
+
+### Requirement: Photo deletion
+Activity owners SHALL be able to delete photos with soft delete and background S3 cleanup.
+
+#### Scenario: Delete photo
+- **WHEN** a user clicks the delete icon on a photo
+- **THEN** the photo status is set to 'deleted' and it disappears from the UI
+- **AND** the S3 object is cleaned up on next page load or periodic cleanup
+
+### Requirement: Photo storage infrastructure
+Photos SHALL be stored in Garage (S3-compatible, self-hosted) running as a Docker container.
+
+#### Scenario: Garage container
+- **WHEN** docker compose starts
+- **THEN** a Garage container is running with an `activity-photos` bucket
+
+### Requirement: Photo privacy disclosure
+Photo storage and EXIF handling SHALL be documented in the privacy manifest.
+
+#### Scenario: Privacy page updated
+- **WHEN** a user visits the privacy page
+- **THEN** it documents photo storage location, EXIF stripping, and deletion behavior