notes.js: Point/Area mode toggle mirroring measure.js's UX — Area
mode accumulates clicked vertices with a live dashed-preview polygon
(own small preview source/layers), a Finish button once 3+ corners
are placed, then the same save form as Point mode.
gpx.js's _addLayers now also renders Polygon features from a file's
"lines" source (fill + outline, filtered by geometry-type — the
existing line layer already only draws LineString, so this is just
two more layers on the same source, not a new bucket) with
popup-on-click like a waypoint, not the track line's hover-summary/
profile-panel behavior. Without this a saved polygon wouldn't have
rendered back on reload.
Fixed along the way: .notes-panel__form/.notes-panel__modes both set
their own `display`, which silently wins over the browser's default
`[hidden] { display: none }` (author styles always beat user-agent
ones) — same gotcha .gpx-panel__action[hidden] already has a comment
about. The form was never actually invisible before being opened.
Verified live: real polygon file (fill/outline render, click ->
popup) and the full Area-mode draw flow (mode switch, live preview,
Finish, form) via headless Chrome. Full test suite: 104 runs, 0
failures — one new backend test confirms a Polygon feature round-
trips through POST /api/gpx/notes.
Known gap (noted in TODO.adoc): the category filter matrix only
re-slices the points source, so toggling "Note" off hides point notes
but not polygon ones.
New map-corner "Add note" control (public/js/notes.js), mirroring
measure.js's click-to-place UX. Click the map, write a short note,
pick an existing .geojson layer file or name a new one — saved via a
new GpxStore#append_feature (grows the target file in place, unlike
save()'s always-disambiguate-the-filename behavior) through a new
POST /api/gpx/notes route.
No new rendering path: a note is just another point in a .geojson
file the Tracks panel's tree already lists, checkboxes, and pops up —
visibility toggling ("layers") comes for free from that existing
machinery, per-file, with no changes needed there.
Points only for now — a polygon mode would need gpx.js's point/line
split taught a third Polygon bucket first, or a saved polygon
wouldn't render back on reload (see TODO.adoc).
Covered by new tests: GpxStore#append_feature (create/append/missing-
path/filename-safety) and the /api/gpx/notes route (auth gate, create,
append, malformed/missing-geometry rejection, 404 on a missing
target). Full suite: 97 runs, 0 failures.
randy