Auction end times, visual flair, and pre-launch cleanup

Auction handling:
- Capture itemEndDate from eBay Browse API and ending_date from ZenMarket
  (Yahoo JP); plumb through results.ends_at column. Permissive ZenMarket
  parser (multiple layouts, JST when offset missing).
- Per-row "Ends" countdown column + "Ending soon" banner on results pages,
  live-ticked by flair.js with urgent/critical tinting under 1h/5m.
- Backfill ends_at for known auctions when their URL reappears in a poll
  (dedup hit no longer drops the new end time).
- Hide ended auctions from result listings by default via
  ResultsQuery.ExcludeEnded; rows stay in the DB.

Visual flair:
- Glassy backdrop-blur v-cards with gradient-mask borders and hover-lift.
- htmx swap fade-in via transient .v-just-swapped class.
- Count-up animation on dashboard stats. All animations gated behind
  prefers-reduced-motion.

eBay condition + region filters (auctions-style scoping):
- items.condition and items.region columns; threaded through item form,
  CreateItem/UpdateItem, scheduler eBay plan input, and previewKey so
  cache invalidates when these change.
- ebay.SearchParams gains conditionIds and itemLocationCountry filters.

Run Now reload + countdown engine:
- Run Now now sets HX-Refresh: true (non-htmx fallback: 303 redirect) so
  the entire results view — best price, chart, badge, last polled —
  reflects the new poll, instead of swapping just one partial.

Pre-launch hardening (P1 set):
- auth.EqualizeLoginTiming on no-such-user branch.
- (*App).serverError centralizes 500s; replaces err.Error() leaks across
  results/settings/items/users/dashboard handlers.
- main.go server: ReadTimeout 30s / WriteTimeout 60s / IdleTimeout 120s
  alongside the existing ReadHeaderTimeout.
- noListFS wrapper blocks static directory listings.
- Credential fields in settings no longer render value=; blank submission
  preserves the saved value, with per-field "Saved in settings / Set in
  config.toml / Not set" status indicator.

Misc:
- -debug flag wires slog to LevelDebug; raw ZenMarket items logged for
  format diagnosis.
- /healthz public endpoint for reverse-proxy probes.
- deploy/veola.service systemd unit template (hardening flags, single
  ReadWritePaths=/var/lib/veola).
- handlers_test.go covers /healthz, setup-gate redirect, auth gate, and
  /login render with httptest + in-memory sqlite.
- best_price_currency on items; templates pick the right symbol per row.
- .gitignore now excludes *.log / veola-debug.log.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/auth/auth.go

@@ -73,6 +73,19 @@ func CheckPassword(hash, plain string) bool {
 	return bcrypt.CompareHashAndPassword([]byte(hash), []byte(plain)) == nil
 }
 
+// dummyHash is a valid bcrypt hash of a throwaway value. It exists only so a
+// login attempt for a non-existent user can still run a real bcrypt
+// comparison, equalizing response time and closing the user-enumeration
+// timing oracle.
+var dummyHash, _ = bcrypt.GenerateFromPassword([]byte("veola-timing-equalizer"), BcryptCost)
+
+// EqualizeLoginTiming performs a bcrypt comparison against a throwaway hash so
+// that a missing username costs roughly the same wall-clock time as a wrong
+// password. Call it on the no-such-user branch of login.
+func EqualizeLoginTiming() {
+	_ = bcrypt.CompareHashAndPassword(dummyHash, []byte("veola-timing-equalizer-x"))
+}
+
 // LogIn writes the user id into the session and rotates the token.
 func (m *Manager) LogIn(ctx context.Context, userID int64) error {
 	if err := m.Sessions.RenewToken(ctx); err != nil {