fix(studio): sidebar left-anchor + pull flow-editor 0.1.2

Two Stefan-reported fixes after the v0.51.x live test:

1. Sidebar icons appeared to shift between collapsed and
   expanded. Mathematically the icons stayed at x=24 (
   ListView padding + AC padding), but the Column's default
   crossAxisAlignment.center re-centered the brand mark
   AND the top indicators (version, connection, channel) on
   every expand → in a 72 px rail the brand sits at x≈36,
   in a 220 px rail it sits at x≈110. Stefan perceived this
   horizontal repositioning of the brand+pills as a shift
   of the icons below.

   Fix: Column.crossAxisAlignment = start + left-pad every
   top item (brand mark, "F∆I Studio" label, version,
   connection pill, channel pill, mini-version, connection
   dot, channel chip) by exactly the same offset the
   destinations use (ListView.padding + AC.padding =
   FaiSpace.md + FaiSpace.md). The whole rail now reads as
   one stable left edge through the expand animation.

2. Pull fai_studio_flow_editor 0.1.2 — fixes the
   "opening hello.yaml shows extract-with-approval content"
   bug by switching `_code.text = ...` to the canonical
   `_code.fullText = ...` setter in the package.

Version: 0.51.2 → 0.51.3
Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

pubspec.yaml

@@ -1,7 +1,7 @@
 name: fai_studio
 description: "F∆I Studio — desktop GUI for the F∆I hub"
 publish_to: 'none'
-version: 0.51.2
+version: 0.51.3
 
 environment:
   sdk: ^3.11.0-200.1.beta