fix(mesh): Meshtastic 3ccc pkc_capable pill + Sideband image interop + critical CBOR wire-bloat fix

Merges in the meshtastic agent's now-finished work alongside this session's
continuation: stock-peer (3ccc) PKI-capability is now stamped through
get_contacts -> refresh_contacts -> MeshPeer.pkc_capable, so a directed DM to/from
a PKC-capable stock Meshtastic peer correctly shows the E2E pill on the Sent row,
not just received messages. Confirmed live: .198 sees "Meshtastic 3ccc" with
pkc_capable=true.

Also fixes two real interop/correctness bugs found while live-testing the
Reticulum <-> Sideband link:
  - Receive: the daemon only ever read LXMF's plain-text content, silently
    dropping native FIELD_IMAGE/FIELD_FILE_ATTACHMENTS fields — a stock
    Sideband/NomadNet photo vanished into a blank-space message. Now decoded
    into the same ContentInline typed envelope our own attachments use.
  - Send: images to a non-archy (stock) peer now use native LXMF FIELD_IMAGE
    instead of our own opaque CBOR wire format, which Sideband can't decode.
  - Root cause of a garbled MC-chunk-fragment bug: TypedEnvelope.v/.sig (the
    OUTER wrapper every message type uses) serialized raw bytes as a CBOR
    array-of-integers instead of a native byte string, bloating every
    message on the wire ~2-3.5x — enough to push even a tiny ReadReceipt
    over the 140-byte single-frame chunking threshold. Root-caused by
    reading ciborium's deserializer source directly (deserialize_bytes only
    works within its internal scratch buffer; deserialize_byte_buf streams
    unbounded).

Frontend: consolidated the attach/record buttons into a single animated "+"
menu (was overflowing the compose row).

857/857 tests pass. Verified live across all 5 deploy-roster nodes.

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

neode-ui/src/views/Mesh.vue

@@ -1276,6 +1276,17 @@ function clearPendingAttachment() {
 
 // ── ContentRef attach + fetch (Phase 3b) ──────────────────────────────────
 const attaching = ref(false)
+// Compose row's "+" attach menu — a single toggle button that pops open a
+// small vertical stack (attach file / voice message) instead of cramming
+// each option in as its own always-visible button (was overflowing).
+const showAttachMenu = ref(false)
+function closeAttachMenuOnOutsideClick(ev: MouseEvent) {
+  if (!showAttachMenu.value) return
+  const target = ev.target as HTMLElement
+  if (!target.closest('.mesh-attach-menu-anchor')) showAttachMenu.value = false
+}
+onMounted(() => document.addEventListener('click', closeAttachMenuOnOutsideClick))
+onUnmounted(() => document.removeEventListener('click', closeAttachMenuOnOutsideClick))
 const attachError = ref<string | null>(null)
 const fetchingCids = ref<Set<string>>(new Set())
 const fetchedUrls = ref<Map<string, string>>(new Map())
@@ -1509,6 +1520,14 @@ let voiceChunks: Blob[] = []
 
 async function startVoiceRecording() {
   if (isRecordingVoice.value || attaching.value || !activeChatPeer.value) return
+  // navigator.mediaDevices is only exposed by the browser in a secure context
+  // (HTTPS, or localhost) — undefined entirely on plain-HTTP LAN nodes like
+  // .116, which throws a confusing "Cannot read properties of undefined"
+  // instead of the permission-style error handled below.
+  if (!navigator.mediaDevices?.getUserMedia) {
+    attachError.value = 'Voice messages need HTTPS (or localhost) — the browser blocks microphone access on plain HTTP'
+    return
+  }
   try {
     voiceRecorderStream = await navigator.mediaDevices.getUserMedia({ audio: true })
   } catch (e) {
@@ -2099,30 +2118,48 @@ function isImageMime(mime?: string): boolean {
                 <button class="mesh-chat-pending-clear" @click="clearPendingAttachment" title="Discard attachment">✕</button>
               </div>
               <div class="mesh-chat-compose-row">
-                <label
-                  v-if="activeChatPeer"
-                  class="glass-button mesh-chat-attach-btn"
-                  :class="{ 'is-busy': attaching }"
-                  :title="attaching ? 'uploading…' : 'Attach file'"
-                >
-                  <input type="file" @change="handleAttachFile" style="display:none;" :disabled="attaching" />
-                  <span v-if="attaching" class="mesh-spinner" aria-hidden="true"></span>
-                  <span v-else>📎</span>
-                </label>
-                <button
-                  v-if="activeChatPeer"
-                  type="button"
-                  class="glass-button mesh-chat-record-btn"
-                  :class="{ 'is-recording': isRecordingVoice }"
-                  :disabled="attaching"
-                  :title="isRecordingVoice ? 'Release to send' : 'Hold to record a voice message'"
-                  @pointerdown.prevent="startVoiceRecording"
-                  @pointerup.prevent="stopVoiceRecording"
-                  @pointerleave="stopVoiceRecordingIfActive"
-                >
-                  <span v-if="isRecordingVoice" class="mesh-spinner" aria-hidden="true"></span>
-                  <span v-else>🎤</span>
-                </button>
+                <div v-if="activeChatPeer" class="mesh-attach-menu-anchor">
+                  <Transition name="mesh-attach-stack">
+                    <div v-if="showAttachMenu" class="mesh-attach-stack">
+                      <label
+                        class="glass-button mesh-chat-attach-btn"
+                        :class="{ 'is-busy': attaching }"
+                        :title="attaching ? 'uploading…' : 'Attach file'"
+                      >
+                        <input
+                          type="file"
+                          @change="(e) => { showAttachMenu = false; handleAttachFile(e) }"
+                          style="display:none;"
+                          :disabled="attaching"
+                        />
+                        <span v-if="attaching" class="mesh-spinner" aria-hidden="true"></span>
+                        <span v-else>📎</span>
+                      </label>
+                      <button
+                        type="button"
+                        class="glass-button mesh-chat-record-btn"
+                        :class="{ 'is-recording': isRecordingVoice }"
+                        :disabled="attaching"
+                        :title="isRecordingVoice ? 'Release to send' : 'Hold to record a voice message'"
+                        @pointerdown.prevent="startVoiceRecording"
+                        @pointerup.prevent="() => { stopVoiceRecording(); showAttachMenu = false }"
+                        @pointerleave="() => { stopVoiceRecordingIfActive(); showAttachMenu = false }"
+                      >
+                        <span v-if="isRecordingVoice" class="mesh-spinner" aria-hidden="true"></span>
+                        <span v-else>🎤</span>
+                      </button>
+                    </div>
+                  </Transition>
+                  <button
+                    type="button"
+                    class="glass-button mesh-chat-plus-btn"
+                    :class="{ 'is-open': showAttachMenu }"
+                    title="Attach"
+                    @click="showAttachMenu = !showAttachMenu"
+                  >
+                    +
+                  </button>
+                </div>
                 <input
                   v-model="messageText"
                   class="mesh-chat-input"