fix(test): move branch descriptions to description.md in push/ignore-branch

Branch description is stored in description.md, not as a field in
meta.json. Move the descriptions for both Main and foo branches to
their respective description.md files so the diff engine sees the
local changes correctly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Matovidlo

test/cli/push/ignore-branch/in/foo/description.md

@@ -0,0 +1 @@
+foo description that must not be pushed

test/cli/push/ignore-branch/in/foo/meta.json

@@ -1,5 +1,4 @@
 {
   "name": "foo",
-  "isDefault": false,
-  "description": "foo description that must not be pushed"
+  "isDefault": false
 }

test/cli/push/ignore-branch/in/main/description.md

@@ -0,0 +1 @@
+main branch description

test/cli/push/ignore-branch/in/main/meta.json

@@ -1,5 +1,4 @@
 {
   "name": "Main",
-  "isDefault": true,
-  "description": "main branch description"
+  "isDefault": true
 }

test/cli/push/ignore-branch/out/foo/description.md

@@ -0,0 +1 @@
+foo description that must not be pushed

test/cli/push/ignore-branch/out/foo/meta.json

@@ -1,5 +1,4 @@
 {
   "name": "foo",
-  "isDefault": false,
-  "description": "foo description that must not be pushed"
+  "isDefault": false
 }

test/cli/push/ignore-branch/out/main/description.md

@@ -0,0 +1 @@
+main branch description

test/cli/push/ignore-branch/out/main/meta.json

@@ -1,5 +1,4 @@
 {
   "name": "Main",
-  "isDefault": true,
-  "description": "main branch description"
+  "isDefault": true
 }