Answer omarchy-shell calls over the shell's own socket (#13435)

* Answer omarchy-shell calls over the shell's own socket

Every omarchy-shell call started a qs ipc client, ~45ms of startup for one
IPC call: a theme switch makes two, and every script-driven OSD, toggle
refresh and lock query paid it too.

The shell now serves a socket in XDG_RUNTIME_DIR, named from its config
path and Wayland display as qs ipc selects its instance, and omarchy-shell
tries it first through socat, which starts in ~5ms. First-party handlers
register as ShellIpc, an IpcHandler that qs ipc still reaches, and the
socket calls only the functions a handler declares with their exact
argument count, allowed by name so QObject methods such as destroy() stay
out of reach.

When the shell ran nothing it answers SKIP, and omarchy-shell asks qs ipc
for its exact answer, so errors, third-party plugins and an unreachable
socket behave as before. A call that may have run is never retried: a
timeout or a connection closed without an answer reports the shell as not
responding.

omarchy-shell shell ping takes ~13-18ms instead of ~61ms, and omarchy-osd
reaches the screen in ~36ms instead of ~77ms. Output and exit status match
the qs ipc path across 26 calls, errors and quiet mode included.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Only accept whole socket replies and retry only unmade connections

A reply cut off after its OK prefix passed for the whole answer, and an
empty reply with socat failing was retried through qs ipc although the
request might already have been delivered.

An answer now counts only once its record separator arrived. socat's own
errors join the reply, so only its connect error, a socket nothing
listens on, falls back to qs ipc beside an explicit SKIP; anything else
is reported as not responding rather than retried.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

shell/shell.qml

@@ -1579,6 +1579,40 @@ ShellRoot {
     }
   }
 
+  // ------------------------------------------------------------ IPC socket
+  //
+  // omarchy-shell reaches the shell here first: a qs ipc client costs ~45ms
+  // to start per call, socat ~5ms. A request is target, method and arguments
+  // separated by unit separators and ended by a record separator. The reply is
+  // "OK" and the output, or "SKIP" when nothing ran (no such target or
+  // function, or the wrong number of arguments), which omarchy-shell hands to
+  // qs ipc for its exact answer. The socket sits in XDG_RUNTIME_DIR, private
+  // to the user like qs ipc's own. Like qs ipc, it belongs to one shell: the
+  // one running this config on this display. omarchy-shell derives the same
+  // name from the same two values.
+  readonly property string ipcSocketPath: Quickshell.env("XDG_RUNTIME_DIR") + "/omarchy-shell-"
+    + Qt.md5(shell.omarchyPath + "/shell\n" + Quickshell.env("WAYLAND_DISPLAY")).slice(0, 16) + ".sock"
+
+  SocketServer {
+    active: shell.omarchyPath !== ""
+    path: shell.ipcSocketPath
+
+    handler: Socket {
+      id: connection
+
+      parser: SplitParser {
+        splitMarker: "\u001e"
+        onRead: function(data) {
+          var fields = String(data).split("\u001f")
+          var result = fields.length >= 2 ? IpcRegistry.call(fields[0], fields[1], fields.slice(2)) : { ran: false }
+          connection.write(result.ran ? "OK\u001f" + result.output + "\u001e" : "SKIP\u001e")
+          connection.flush()
+          connection.connected = false
+        }
+      }
+    }
+  }
+
   // --------------------------------------------------- image selector IPC
 
   function imagePickerItem() {
@@ -1586,7 +1620,7 @@ ShellRoot {
     return loader && loader.item ? loader.item : null
   }
 
-  IpcHandler {
+  ShellIpc {
     target: "image-selector"
 
     function open(imageDirs: string,
@@ -1637,7 +1671,7 @@ ShellRoot {
 
   // ---------------------------------------------------------- shell IPC
 
-  IpcHandler {
+  ShellIpc {
     target: "shell"
 
     function ping(): string {