Replaces "clear intro after first send", which dropped the message
for any subscriber still queued on a slower cadence.
- Each non-empty admin save bumps a per-locale version counter on
the tree. The dispatcher includes the intro only for recipients
whose last-seen version is behind, then advances their watermark
after a successful send. Webtrees users get a per-user watermark;
external addresses share one tree-level watermark. Re-saving the
same text is a no-op.
- The preferences page now shows delivery progress per locale:
"Delivered to X of Y subscriber(s)" plus a collapsible Pending
list with name + email of each subscriber who hasn't received
the current intro yet, and a single "External recipients (N)"
row when the external watermark is behind.
- README rewritten to reflect every feature shipped since the
initial commit (BockenTheme skin, embedded avatars, relationship
labels, kin-distance filter, per-user cadence, bilingual subject
prefix, locale-aware subject date, SiteUser as From, three
subscriber sources, Markdown intro with personalisation tokens).
Alexander
90ad060421
