refactor(street-level): slim Mapillary tile proxy — memory cache only, no server holds

Drop the disk tile cache (.gev-cache/mapillary/tiles, background sweep,
size cap, legacy retrim), the server-side 401/403/429 holds, the upstream
concurrency semaphore and per-waiter abort bookkeeping. The client already
pauses on 429 and stops on a rejected key.

Keep: server-side token, {configured}-only status, strict coverage path
validation (z11-14), image-layer trimming, same-site gate and per-IP limit,
HTTPS redirect pinning to the tile origin, the streamed size cap, the error
mapping the client reads, a 24 h byte-budget LRU memory cache, in-flight
coalescing via the shared coalesceProxyRequest, and browser Cache-Control.

Routes and constants fold into mapillary.js and mapillary/tiles.js.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

scripts/package-boundaries.json

@@ -188,8 +188,6 @@
     "exports": ["./server/providers/mapillary"],
     "modules": [
       "server/providers/mapillary.js",
-      "server/providers/mapillary/routes.js",
-      "server/providers/mapillary/constants.js",
       "server/providers/mapillary/tiles.js",
       "server/providers/mapillary/trim.js",
       "server/providers/common/same-site.js",