route-surface-breakdown (Phase 1): Planner-path surface/waytype bars

Synchronous path + rendering for the surface/waytype breakdown:
- map-core `computeSurfaceBreakdown(coords, surfaces, highways)` → distance-
  weighted metres per surface + waytype category (unit-tested);
- `SurfaceBreakdownSchema` in @trails-cool/api;
- nullable `surfaceBreakdown` jsonb on routes + activities;
- Planner `SaveToJournalButton` computes it from the BRouter waytags already in
  routeData and sends it; `api.save-to-journal` forwards it; the journal route
  callback validates + persists (journal is the authoritative validator);
- `SurfaceBreakdown` component (stacked bars per dimension, map-core palettes,
  legend category · % · km largest-first, unknown → "other", hidden when empty)
  on route + activity detail; journal gains a @trails-cool/map-core dep;
- i18n journal.surface.* (en + de).

Phase 2 (async Overpass backfill + SSE for imports/uploads, and the e2e that
seeds a breakdown) follows in a separate PR.

Tests: computeSurfaceBreakdown unit (map-core 36); SurfaceBreakdown component
(jsdom, journal 326). typecheck + lint green; verified in the browser.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

packages/db/src/schema/journal.ts

@@ -91,6 +91,15 @@ export const magicTokens = journalSchema.table("magic_tokens", {
  */
 export type Visibility = "private" | "unlisted" | "public";
 
+/**
+ * Distance-weighted surface/waytype breakdown (metres per category), derived
+ * from BRouter waytags at Planner save or backfilled via Overpass.
+ */
+export type SurfaceBreakdown = {
+  surface: Record<string, number>;
+  highway: Record<string, number>;
+};
+
 export const routes = journalSchema.table("routes", {
   id: text("id").primaryKey(),
   ownerId: text("owner_id")
@@ -106,6 +115,7 @@ export const routes = journalSchema.table("routes", {
   elevationLoss: real("elevation_loss"),
   dayBreaks: jsonb("day_breaks").$type<number[]>(),
   tags: jsonb("tags").$type<string[]>(),
+  surfaceBreakdown: jsonb("surface_breakdown").$type<SurfaceBreakdown>(),
   plannerState: bytea("planner_state"),
   visibility: text("visibility").$type<Visibility>().notNull().default("private"),
   /**
@@ -173,6 +183,9 @@ export const activities = journalSchema.table("activities", {
   description: text("description").default(""),
   // Sport / activity type (NULL = unspecified). See SPORT_TYPES above.
   sportType: text("sport_type").$type<SportType>(),
+  // Distance-weighted surface/waytype breakdown (backfilled via Overpass for
+  // imported/uploaded activities). NULL until derived.
+  surfaceBreakdown: jsonb("surface_breakdown").$type<SurfaceBreakdown>(),
   gpx: text("gpx"),
   geom: lineString("geom"),
   startedAt: timestamp("started_at", { withTimezone: true }),