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/waypoint-notes/specs/waypoint-notes/spec.md

@@ -0,0 +1,46 @@
+## ADDED Requirements
+
+### Requirement: Per-waypoint text notes
+Each waypoint SHALL support an optional plain-text note synced via Yjs.
+
+#### Scenario: Add note to waypoint
+- **WHEN** a user clicks the note area under a waypoint in the sidebar and types text
+- **THEN** the note is stored in the waypoint's Y.Map as a `note` string field
+- **AND** auto-saves on blur
+
+#### Scenario: Note syncs to participants
+- **WHEN** a user adds or edits a waypoint note
+- **THEN** all other participants see the update in real-time via Yjs
+
+### Requirement: Map note indicators
+Waypoint markers with notes SHALL show a visual indicator on the map.
+
+#### Scenario: Note icon on marker
+- **WHEN** a waypoint has a note
+- **THEN** its map marker shows a small note icon
+
+#### Scenario: Note tooltip
+- **WHEN** a user hovers or taps a marker with a note
+- **THEN** the note text appears in a tooltip
+
+### Requirement: Notes in GPX export
+Waypoint notes SHALL be exported as `<desc>` elements in GPX output.
+
+#### Scenario: Export notes
+- **WHEN** a user exports a plan with waypoint notes
+- **THEN** each waypoint's note appears as a `<desc>` element in the GPX file
+
+### Requirement: Nearby POI display
+When a waypoint is selected, nearby POIs from OpenStreetMap SHALL be shown on the map and in the sidebar.
+
+#### Scenario: POI lookup
+- **WHEN** a user selects a waypoint
+- **THEN** nearby POIs are fetched from the Overpass API and displayed as small markers on the map and as a list in the sidebar
+
+### Requirement: Snap waypoint to POI
+Users SHALL be able to move a waypoint to a nearby POI's exact coordinates.
+
+#### Scenario: Snap to POI
+- **WHEN** a user clicks a nearby POI
+- **THEN** the waypoint moves to the POI's coordinates
+- **AND** the POI's name and type are added as a note prefix (e.g., "Campsite - Waldcamp Fichtelberg")