Add .ics calendar feed support

doot reads Google Calendar through a service account, by calendar ID. That
cannot consume an .ics URL, and it cannot see a calendar subscribed to inside a
personal Google account either, because Google does not allow re-sharing a
subscribed calendar. Published schedules — sports fixtures, school terms, bin
collections — are distributed almost exclusively as .ics, so none of them could
be added at all.

Feeds are now fetched on the normal calendar refresh and merged into
calendar_events alongside Google events, so the timeline, widget and everything
downstream keep seeing one list and needed no changes.

Failure handling is deliberately asymmetric. A Google error is still returned as
an error, unchanged, so an outage there surfaces. A single failing feed is
recorded against that feed and skipped, because one dead URL should not take the
whole calendar down — and last_error is shown in settings, since a feed that has
quietly stopped resolving otherwise looks identical to a team with no games
left.

The parser handles what real feeds actually contain: line unfolding, CRLF and
LF, UTC / TZID / VALUE=DATE times, and escaped text. Two details worth naming:
a TZID time is wall-clock in that zone, and reading it as UTC would put a 1:15pm
Pacific kickoff on the timeline at 1:15pm local — wrong by the offset but
entirely plausible-looking. And non-calendar content is a hard error rather than
zero events, because an HTML error page from a moved feed URL is the common
failure and "no events" reads as success.

RRULE is deliberately unsupported: every schedule feed this targets expands
recurrence itself, one VEVENT per fixture, and a correct expansion is a large
amount of subtle code. A recurring event appears once rather than wrongly.

Settings gains an add/enable/disable/remove UI. webcal:// links are accepted and
rewritten, since that is how feeds are usually advertised.

16 parser tests, 5 store tests. Verified against the real Seattle Seahawks feed:
21 events, all with valid times.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018AwnALZL6bD4VBtATDVv3B

1 files changed, 3 insertions, 0 deletions

diff --git a/internal/handlers/settings.go b/internal/handlers/settings.go
index d140aaf..d6d78c0 100644
--- a/internal/handlers/settings.go
+++ b/internal/handlers/settings.go
@@ -23,6 +23,7 @@ func (h *Handler) HandleSettingsPage(w http.ResponseWriter, r *http.Request) {
 	}
 
 	googleTasksToken, _ := h.store.GetOAuthToken(api.GoogleTasksOAuthSource)
+	icsFeeds, _ := h.store.GetICSFeeds()
 
 	data := struct {
 		Configs               map[string][]models.SourceConfig
@@ -34,6 +35,7 @@ func (h *Handler) HandleSettingsPage(w http.ResponseWriter, r *http.Request) {
 		GoogleTasksOAuthReady bool
 		GoogleTasksConnected  bool
 		GoogleTasksError      string
+		Feeds                 []icsFeedView
 	}{
 		Configs:               bySource,
 		Sources:               []string{"trello", "gcal", "gtasks"},
@@ -43,6 +45,7 @@ func (h *Handler) HandleSettingsPage(w http.ResponseWriter, r *http.Request) {
 		WebAuthnEnabled:       h.WebAuthnEnabled,
 		GoogleTasksOAuthReady: h.googleTasksOAuthConfig != nil,
 		GoogleTasksConnected:  googleTasksToken != nil,
+		Feeds:                 toICSFeedViews(icsFeeds),
 		GoogleTasksError:      r.URL.Query().Get("google_tasks_error"),
 	}