10-Mar-2026 — map hang, GPX route parsing, mail API resilience, walk search layout

build 515 — commit 0cad242

Root cause: GPX parser only handled <trk>/<trkpt> (track) elements but ignored <rte>/<rtept> (route) elements. 37 of 39 Sevenoaks walking route GPX files use <rte> format, so only 2 routes were rendering on the map
Fix: added parseRoute() and parseRoutePoints() methods to convert <rte>/<rtept> elements into renderable GpxTrack objects alongside existing <trk> parsing
Waypoint dedup: changed parseWaypoints() from selecting "wpt, rtept" to just "wpt" — <rtept> elements are now parsed as route tracks, not waypoints, preventing duplicate rendering

Root cause: Dragging/zooming the map triggered an infinite feedback loop — moveend → loadRoutes() → layer reassignment + fitBounds → Leaflet re-render → moveend again
Debounced viewport handler: 300ms debounce on moveend/zoomend prevents rapid-fire reloads during panning
Re-entrancy guard: loadRoutesInProgress flag skips concurrent loadRoutes() calls
Suppress programmatic events: suppressViewportHandler flag prevents layer/bounds assignment from re-triggering the viewport handler (cleared after 200ms)
Skip fitBounds on viewport reloads: loadRoutes(skipFitBounds) parameter prevents calculateFitBounds on user-initiated pan/zoom, which was the primary loop trigger
Removed cache eviction on viewport change: the viewport filtering already uses currentBounds.intersects() on cached data, so deleting and re-fetching GPX on every drag was unnecessary

Short-circuit when no API key: MailMessagingService.initialise() checks mailConfig.apiKey after loading config — if absent, skips all Brevo API calls (account, lists, folders, templates) and sets safe empty defaults. Zero 401 errors in the console
Short-circuit on account error: if the account query fails (invalid key), remaining Brevo calls are skipped with empty defaults
Senders list guard: MailSendersListComponent waits for the mailMessagingConfig via the events() observable before calling senders/domain APIs — skips if accountError is set
Create-or-amend sender guard: checks brevoAccountConfigured() before calling querySenders()
Mail provider stats guard: calculateMailProviderStats() handles this.list being undefined when Brevo lists fail to load, showing "No Brevo lists available" instead of crashing
List key values null safety: added ?. and || [] fallback when brevo.lists.lists is undefined
Alert icon: changed error alert icon from faCircleCheck to faExclamationTriangle for the account error panel

Root cause: responseFrom() used .subscribe() + .toPromise() on a shared observable, causing two subscriptions and duplicate HTTP requests
Fix: replaced with single firstValueFrom() call — one subscription, one HTTP request, proper error propagation via throw

Root cause: restoreSensitiveFields() in the backend config controller treated both missing keys AND falsy values ("", null) as "restore from DB", making it impossible to clear the API key
Fix: changed condition from !(k in incoming) || !incoming[k] to !(k in incoming) — only restores when the key is truly absent (redacted), not when explicitly cleared

Root cause: MailMessagingService.initialise() created new subscriptions to committeeConfig and systemConfigService on every call, causing accumulated subscriptions that re-emitted config and overwrote unsaved edits
Fix: moved one-time subscriptions to the constructor; acceptNextConfigEmission flag in MailSettingsComponent prevents subscription emissions from overwriting local edits except after save or undo

Changed domain endpoints from path parameters (/domains/:domainName/configuration) to query parameters (/domains/configuration?domainName=...) across backend routes and frontend service