feat(studio): editor 0.3 — endpoints stay put + node context menu

Picks up fai_studio_flow_editor 0.3.0 (commit 296e5bf):

 - inputs/outputs endpoints now live in the layout sidecar
   like every other node — they stop drifting when the
   operator drags a step. The "outputs panel jumps when I
   touch anything" pain Stefan flagged is gone by
   construction.
 - Right-click on any step in the graph tab opens a popup
   menu: Duplicate (with unique id + offset), Disconnect
   all inputs (clears with-field values but keeps keys),
   Delete.
 - Floating Reset Layout button on the canvas next to
   Fit-to-screen — wipes the sidecar and re-runs
   AutoLayout from scratch + auto-fits, for when manual
   drags have drifted into spaghetti.

Version 0.52.4 -> 0.53.0 (minor bump — first new
operator-visible editor feature surface since 0.52).

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

pubspec.lock

@@ -125,10 +125,10 @@ packages:
     description:
       path: "."
       ref: main
-      resolved-ref: ad2e5b50d5201c9b97329b02e2223d6e599545f1
+      resolved-ref: "296e5bfd018e523e7527abc457de3a62c1ba5139"
       url: "https://git.flemming.ai/fai/studio-flow-editor"
     source: git
-    version: "0.2.2"
+    version: "0.3.0"
   fake_async:
     dependency: transitive
     description: