shell: land the owned message delegate and the speech fixes

Applied 0009 then 0008 (0008's re-synthesize control calls a function 0009
adds). Casey applied and reloaded; verified against a running shell rather
than from a clean load.

0009 Speech.qml
  stop() could not stop. playProc ran `sh -c "mpv ... || ffplay ..."` — a
  compound command, so sh does not exec-replace itself and SIGTERM killed the
  wrapper while the player kept sounding as an orphan. Reproduced directly.
  That is the back-to-back TTS slam: every stop left audio playing and the
  next speak started a second player over it. Shell dropped; the pid held is
  now the pid making noise. ffplay fallback deleted rather than repaired —
  needing a fallback is what forced the wrapper that broke the kill.
  resynthesize() added, bypassing the cache: the button existed for "that came
  out wrong" and, being keyed on the same text, always replayed the identical
  file. synthesizing/playing split out of one `speaking` boolean.

0008 AiChat.qml
  One line: delegate AiMessage -> AgentMessage. The vendor block named 8 tools;
  the registry holds 19. The 11 it could not see were exactly the interiority
  surface — outfit, nickname, subagent, atmosphere, reach, consult, itinerary,
  todo, schedule, halt, intrusive.

  regenerate and edit dropped deliberately, per Casey: text regeneration is not
  possible (Ai.regenerate() already returned advice) and there is no in-place
  edit (the vendor wrote to a local array the server never sees). delete is
  armed and states that it hides locally only. Do not restore them.

Queue entries removed here, per the directory's own discipline.

surfaces/quickshell/modules/ii/sidebarLeft/AiChat.qml

@@ -6,6 +6,7 @@ import qs.modules.common.functions
 import qs.modules.souveraine.subconscious
 import qs.modules.ii.sidebarLeft.aiChat
 import qs.modules.souveraine.island
+import qs.modules.souveraine.agent
 import QtQuick
 import QtQuick.Controls
 import QtQuick.Layouts
@@ -446,7 +447,7 @@ Inline w/ backslash and round brackets \\(e^{i\\pi} + 1 = 0\\)
                         return message?.visibleToUser ?? true;
                     })
                 }
-                delegate: AiMessage {
+                delegate: AgentMessage {
                     required property var modelData
                     required property int index
                     messageIndex: index