Make private-message delivery status legible and accessible (#1356)

* Make private-message delivery status legible and accessible

The delivery indicator is the most stress-relevant signal in an
off-grid messenger, but it is hard to read:

- The status glyphs are 10pt icons whose only explanation is a
  `.help()` tooltip, which does not exist on iOS.
- Delivered vs read is the same double-checkmark distinguished only by
  colour.
- No case carries an accessibility label, so VoiceOver announces
  nothing.
- Two failure reasons ("Not delivered", "Encryption failed") bypass the
  localized reason catalog and are hardcoded English.

Changes (presentation only; the DeliveryStatus enum and the
contract-tested `displayText` are untouched):

- Add `DeliveryStatus.bitchatDescription`, a localized app-layer
  description, used as the macOS tooltip, a VoiceOver label on every
  status glyph, and — on iOS, where tooltips don't exist — a
  tap-to-reveal caption under the message.
- Failure reasons stay visible as a red caption without a tap.
- Read vs delivered is now legible without colour: read uses
  filled-circle checkmarks.
- Route the two hardcoded failure reasons through the localized catalog.

New strings are added source-language (en) only.

* Show the failure reason on failed media messages too

TextMessageView gained a visible red failure caption (the status
glyph's .help() tooltip does not exist on iOS), but MediaMessageView
still rendered the bare glyph — so a failed voice-note or image send
showed only a 10pt red triangle with no reason on iOS. Add the same
failure caption to media messages.

* Collapse revealed delivery detail when the status changes

A caption revealed while a message was "sending" stayed open and
silently morphed through later statuses (sent, delivered, read).
Reset showDeliveryDetail when the snapshotted DeliveryStatus changes.

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

* Add tap-to-reveal delivery detail to media rows

Media rows showed the same delivery glyphs as text rows but offered no
way to explain them on iOS, where .help() tooltips don't exist. Mirror
the text-row pattern: the glyph is now a button that reveals the
localized status caption below the header, failure reasons stay
visible without a tap, and the revealed caption collapses when the
status advances.

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

* Localize the remaining voice-note failure reasons

ChatMediaTransferCoordinator still passed hardcoded English reasons
into .failed(reason:), which now surface verbatim in the always-visible
failure caption. Route them through String(localized:) under the
existing content.delivery.reason.* convention.

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

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

bitchat/ViewModels/ChatViewModelBootstrapper.swift

@@ -100,7 +100,7 @@ private extension ChatViewModelBootstrapper {
                     category: .session
                 )
                 viewModel.conversations.setDeliveryStatus(
-                    .failed(reason: "Not delivered"),
+                    .failed(reason: String(localized: "content.delivery.reason.not_delivered", comment: "Failure reason shown when the router gave up delivering a message")),
                     forMessageID: messageID
                 )
             }