docs: F-Droid install guide with repo URL + fingerprint; backlog daily-driver ideas

README gains a real install path: add the self-hosted repo
(apps.dev.jeanlucmakiola.de/dev/fdroid/repo, fingerprint inline and as an
add-repo link), search, install. Verified live against the repo index.

Roadmap gains the approved daily-driver idea backlog (unscheduled): slot-tap
create, drag & drop rescheduling, agenda view, pinch-zoom, reminder
snooze/dismiss + default reminder, duplicate event, per-event color,
.ics share/receive, app shortcuts, jump-to-date — plus the consciously
rejected list (network-dependent features, NL quick entry).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.planning/ROADMAP.md

@@ -118,6 +118,31 @@ Deliberately deferred (add only if needed):
 
 Order is indicative — community feedback after V1 may re-prioritize.
 
+## Idea backlog — Daily-driver polish (captured 2026-06-11, all approved as ideas, unscheduled)
+
+Interaction:
+- Tap/long-press an empty slot in day/week → create form prefilled with that time
+- Drag & drop rescheduling in day/week (recurring drops reuse the scope dialog) — big-ticket, own slice
+- Agenda view (fourth view: upcoming events grouped by day; natural widget data source)
+- Pinch-to-zoom time scale in day/week
+
+Reminders, round two:
+- Snooze + dismiss actions on the notification (snooze needs an exact-alarm/WorkManager decision)
+- Settings default reminder applied to new events
+
+Event niceties:
+- Duplicate event (detail action → prefilled create form)
+- Per-event color (`Events.EVENT_COLOR`, OptionCard picker in the form)
+- Share event as .ics + open/receive .ics into a prefilled create form (front-runs v3 ICS import)
+
+Small delights:
+- App shortcuts (launcher long-press → New event), maybe a quick-settings tile
+- Jump to date (un-cut from V1 — drawer date picker)
+
+Consciously rejected: travel time / weather / smart suggestions (network,
+core-promise conflict), natural-language quick entry (high effort,
+locale-fragile, prefilled form already covers fast entry).
+
 ## Idea backlog — Locations & People (captured 2026-06-11, undecided)
 
 Beyond classic calendar-client scope; discussed, deliberately not planned