feat(train): routes kept as sealed rows, planned on the map (ADR 0030, D44)

Routes are synced `route` rows (the model `SavedRoute`, as Flutter has a
`Route`), sealed as plans are; the migration `routes` only creates the
table, its space index and its cascade to the sync engine's spaces. A
route's payload holds its name, activity, profile, waypoints and the way
planned, points and elevations delta-coded and gzipped.

Home gets a fourth tab, Routes, and the planner: waypoints tapped on the
map, held and dragged, the last undone, a new route's first where the
phone is (GPS through the recorder's channel), the way planned by the
instance's BRouter after each change, an earlier answer dropped; its
distance, climb, descent, elevation and surfaces under the map.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/train/halkyon_train_flutter/lib/l10n/app_en.arb

@@ -481,5 +481,48 @@
   "dayCelsius": "{value} °C",
   "@dayCelsius": {"placeholders": {"value": {"type": "String", "example": "33.4"}}},
   "daySkinDeviation": "{value} °C from your usual at night",
-  "@daySkinDeviation": {"placeholders": {"value": {"type": "String", "example": "−0.2"}}}
+  "@daySkinDeviation": {"placeholders": {"value": {"type": "String", "example": "−0.2"}}},
+  "homeRoutes": "Routes",
+  "routesNew": "New route",
+  "routesEmptyTitle": "No routes yet",
+  "routesEmptyHint": "Tap the map to set waypoints, and your instance plans the way between them on paths and roads, with its climb and surfaces.",
+  "routeLocked": "A route that doesn't open here",
+  "routeTitle": "Route",
+  "routeNewTitle": "New route",
+  "routeName": "Name",
+  "routeActivity": "For",
+  "routeActivityAny": "Any activity",
+  "routeProfile": "Planned for",
+  "routeProfileRun": "Running",
+  "routeProfileHike": "Hiking",
+  "routeProfileRoadBike": "Road bike",
+  "routeProfileTrekkingBike": "Trekking bike",
+  "routeProfileGravel": "Gravel bike",
+  "routeProfileMtb": "Mountain bike",
+  "routeTapHint": "Tap the map to add a waypoint; hold one and drag it to move it.",
+  "routeUndo": "Take the last waypoint off",
+  "routePlanning": "Planning…",
+  "routeRefusedInvalid": "A waypoint too many, or one off the map.",
+  "routeRefusedTooOften": "Planned too often: try again in a minute.",
+  "routeRefusedNoRoute": "No way found there: a waypoint may be off the paths, or outside the region your instance plans in.",
+  "routeRefusedUnreachable": "Your instance can't be reached to plan the way.",
+  "routeNotOffered": "Your instance doesn't plan routes.",
+  "routeAscent": "{metres} m up",
+  "@routeAscent": {"placeholders": {"metres": {"type": "int"}}},
+  "routeDescent": "{metres} m down",
+  "@routeDescent": {"placeholders": {"metres": {"type": "int"}}},
+  "routeSummary": "{distance} · {ascent}",
+  "@routeSummary": {"description": "A route in the list: its distance and climb.", "placeholders": {"distance": {"type": "String", "example": "12.3 km"}, "ascent": {"type": "String", "example": "120 m up"}}},
+  "routeSurfaces": "Surfaces",
+  "surfacePaved": "Paved",
+  "surfaceCompacted": "Compacted",
+  "surfaceGravel": "Gravel",
+  "surfaceNatural": "Natural ground",
+  "surfaceUnknown": "Not known",
+  "routeSave": "Save",
+  "routeNotSaved": "The route wasn't saved.",
+  "routeDelete": "Delete",
+  "routeDeleteTitle": "Delete this route?",
+  "routeDeleteMessage": "It's deleted on all your devices.",
+  "routeDeleted": "Route deleted"
 }