feat(settings): add Stacks section for stack workflow preferences (#1366)

Move the browser-local Deploy progress, Progress style, and Diff preview
before save controls out of Appearance into a new Stacks section under the
Infrastructure group. These are stack lifecycle and editor workflow
preferences, not visual style, so Settings now groups them where operators
expect to find them.

Add a browser-local masthead scope so these localStorage-backed sections read
SCOPE browser instead of the misleading global, and apply it to both
Appearance and Stacks. Control behavior, storage keys, and backing hooks are
unchanged; this is an information-architecture move only.

docs/features/app-store.mdx

@@ -117,7 +117,7 @@ Clicking **Deploy** runs the following sequence:
 
 ## Watching the deploy
 
-Sencho can stream the live `docker compose` output for every template install. Open **Settings › Appearance › Display** and enable **Deploy progress**; from then on, every App Store deploy streams its output. In Modal style it opens a structured log modal you can minimise to a pill that follows you across navigation; in Inline style it shows as that pill, which opens the same log on click. See [Deploy Progress](/features/deploy-progress) for the full reference.
+Sencho can stream the live `docker compose` output for every template install. Open **Settings › Infrastructure › Stacks** and enable **Deploy progress**; from then on, every App Store deploy streams its output. In Modal style it opens a structured log modal you can minimise to a pill that follows you across navigation; in Inline style it shows as that pill, which opens the same log on click. See [Deploy Progress](/features/deploy-progress) for the full reference.
 
 <Note>
   Deploying a template requires the `stack:create` permission on the target node, which **admin** and **node-admin** roles hold by default. The Deploy button stays disabled when your account does not have it.

docs/features/appearance.mdx

@@ -50,5 +50,5 @@ The **Display** group holds the remaining per-browser preferences:
 
 - **Density** switches between **Comfortable** (roomy rows, the default) and **Compact** (tighter rows and tiles that fit more on screen for dense dashboards).
 - **Top navigation labels** shows text labels beside the top navigation icons. Turn it off for an icon-only bar; the destinations stay reachable by hover tooltip, accessible name, and the command palette. On the phone layout the navigation always keeps its labels. With labels off, **Top navigation alignment** chooses whether the icon-only bar sits to the left or centered.
-- **Deploy progress** toggles live output streaming for deploy, restart, update, install, and Git operations, and **Progress style** chooses Modal or Inline presentation.
-- **Diff preview before save** toggles a side-by-side diff of compose and env edits before they are written to disk.
+
+Deploy-progress behavior and the diff-preview-before-save step are stack workflow preferences, so they live in **Settings → Infrastructure → Stacks**, not here.

docs/features/deploy-progress.mdx

@@ -7,7 +7,7 @@ When you trigger a stack action that runs through `docker compose` (Deploy, Upda
 
 ## Showing, hiding, and styling deploy progress
 
-Deploy progress is **on by default**. To run operations without it, open **Settings > Appearance > Display** and turn off **Deploy progress**. While it is on, **Progress style** chooses how it appears:
+Deploy progress is **on by default**. To run operations without it, open **Settings > Infrastructure > Stacks** and turn off **Deploy progress**. While it is on, **Progress style** chooses how it appears:
 
 - **Modal** (the default): a centered overlay that opens automatically and streams the full structured log.
 - **Inline**: a quiet status band on the stack detail itself, with the full log a click away under **View output**.
@@ -15,7 +15,7 @@ Deploy progress is **on by default**. To run operations without it, open **Setti
 The choices are saved to the current browser only and synced across tabs in the same browser without a reload.
 
 <Frame>
-  <img src="/images/deploy-progress/setting-toggle.png" alt="Settings Appearance Display panel with the deploy progress toggle." />
+  <img src="/images/deploy-progress/setting-toggle.png" alt="Settings Stacks panel with the deploy progress toggle." />
 </Frame>
 
 ## Using the modal

docs/features/editor.mdx

@@ -127,7 +127,7 @@ The same controls apply to the `compose.yaml` and `.env` editors.
 
 ## Diff preview before save
 
-When **Diff preview before save** is enabled in **Settings → Appearance**, clicking **Save & Deploy** or **Save Only** opens a side-by-side diff modal before anything is written to disk. The left pane is the on-disk content; the right pane is your unsaved edits with additions highlighted in green. The footer reads `ON DISK → UNSAVED` so the panes are unambiguous.
+When **Diff preview before save** is enabled in **Settings → Infrastructure → Stacks**, clicking **Save & Deploy** or **Save Only** opens a side-by-side diff modal before anything is written to disk. The left pane is the on-disk content; the right pane is your unsaved edits with additions highlighted in green. The footer reads `ON DISK → UNSAVED` so the panes are unambiguous.
 
 <Frame>
   <img src="/images/compose-diff-preview/diff-modal.png" alt="Diff preview modal showing side-by-side YAML diff with the unsaved version on the right and an ON DISK to UNSAVED legend in the footer" />