docs: dissolve Guides into feature homes (SD-2873)

Top-level Guides was a junk drawer mixing product surfaces, migration
docs, and internal contributor material. Move every page to where the
feature actually lives so each section reads as one coherent topic.

Editor:
- Collaboration > Storage (was Guides > Storage)
- Custom UI > Navigation (was Guides > Stable navigation)
- Proofing > Overview, Custom provider (was Guides > Proofing)
- Theming > Custom themes, CSS variable migration (was Guides + Migration)

Document API:
- Migration (was Guides > Migration > Document API)

Resources:
- Upgrade guides > Breaking changes v1, Migrate from ProseMirror

Hidden:
- TypeScript migration (internal contributor doc, not consumer-facing)

Drop the entire Guides nav group. Add redirects so every old
/guides/* URL resolves to its new home. Sweep cross-references.

Also fix the accessibility page: the docs referenced
superdoc.isHighContrastMode (no such public property); replace
with the real setHighContrastMode(value) method.

Author: caio-pizzol

apps/docs/docs.json

@@ -104,6 +104,7 @@
                   "editor/custom-ui/comments",
                   "editor/custom-ui/track-changes",
                   "editor/custom-ui/selection-and-viewport",
+                  "editor/custom-ui/navigation",
                   "editor/custom-ui/document-control",
                   "editor/custom-ui/api-reference"
                 ]
@@ -126,6 +127,7 @@
                   "editor/collaboration/quickstart",
                   "editor/collaboration/upgrade-to-collaboration",
                   "editor/collaboration/configuration",
+                  "editor/collaboration/storage",
                   {
                     "group": "Guides",
                     "pages": [
@@ -136,6 +138,14 @@
                   }
                 ]
               },
+              {
+                "group": "Proofing",
+                "pages": ["editor/proofing/overview", "editor/proofing/custom-provider"]
+              },
+              {
+                "group": "Theming",
+                "pages": ["editor/theming/custom-themes", "editor/theming/css-variable-migration"]
+              },
               {
                 "group": "PDF",
                 "pages": ["editor/pdf", "editor/pdf/whiteboard"]
@@ -153,7 +163,8 @@
                   "document-api/overview",
                   "document-api/reference/index",
                   "document-api/common-workflows",
-                  "document-api/available-operations"
+                  "document-api/available-operations",
+                  "document-api/migration"
                 ]
               },
               {
@@ -210,35 +221,17 @@
               }
             ]
           },
-          {
-            "group": "Guides",
-            "pages": [
-              "guides/general/storage",
-              "guides/general/stable-navigation",
-              "guides/general/custom-themes",
-              {
-                "group": "Proofing",
-                "pages": ["guides/general/proofing", "guides/general/custom-proofing-provider"]
-              },
-              {
-                "group": "Migration",
-                "pages": [
-                  "guides/migration/document-api",
-                  "guides/migration/prosemirror",
-                  "guides/migration/breaking-changes-v1",
-                  "guides/migration/typescript-migration",
-                  "guides/migration/css-variables"
-                ]
-              }
-            ]
-          },
           {
             "group": "Resources",
             "pages": [
               "guides/general/accessibility",
               "resources/telemetry",
               "guides/general/security",
-              "resources/license"
+              "resources/license",
+              {
+                "group": "Upgrade guides",
+                "pages": ["guides/migration/breaking-changes-v1", "guides/migration/prosemirror"]
+              }
             ]
           }
         ]
@@ -298,6 +291,34 @@
     "dismissible": true
   },
   "redirects": [
+    {
+      "source": "/guides/general/storage",
+      "destination": "/editor/collaboration/storage"
+    },
+    {
+      "source": "/guides/general/stable-navigation",
+      "destination": "/editor/custom-ui/navigation"
+    },
+    {
+      "source": "/guides/general/custom-themes",
+      "destination": "/editor/theming/custom-themes"
+    },
+    {
+      "source": "/guides/general/proofing",
+      "destination": "/editor/proofing/overview"
+    },
+    {
+      "source": "/guides/general/custom-proofing-provider",
+      "destination": "/editor/proofing/custom-provider"
+    },
+    {
+      "source": "/guides/migration/document-api",
+      "destination": "/document-api/migration"
+    },
+    {
+      "source": "/guides/migration/css-variables",
+      "destination": "/editor/theming/css-variable-migration"
+    },
     {
       "source": "/bring-your-own-ui/:path*",
       "destination": "/editor/custom-ui/:path*"

…s/docs/guides/migration/document-api.mdx apps/docs/document-api/migration.mdxapps/docs/guides/migration/document-api.mdx renamed to apps/docs/document-api/migration.mdx apps/docs/guides/migration/document-api.mdx renamed to apps/docs/document-api/migration.mdx

@@ -53,7 +53,7 @@ Each surface is configured via `modules.<name>` in the [SuperDoc configuration](
   <Card title="Collaboration" icon="users" href="/editor/collaboration/overview">
     Real-time multi-user editing with Yjs (separate top-level section)
   </Card>
-  <Card title="Proofing" icon="check-check" href="/guides/general/proofing">
+  <Card title="Proofing" icon="check-check" href="/editor/proofing/overview">
     Provider-based spell check on the layout-engine editor surface
   </Card>
 </CardGroup>

apps/docs/editor/built-in-ui/overview.mdx

@@ -107,4 +107,4 @@ See the working repo examples for two complete provider integrations:
 ## Next steps
 
 - See [Configuration](/editor/superdoc/configuration#proofing) for all options
-- See [Custom proofing provider](/guides/general/custom-proofing-provider) to connect your own service
+- See [Custom proofing provider](/editor/proofing/custom-provider) to connect your own service

apps/docs/guides/general/storage.mdx …ps/docs/editor/collaboration/storage.mdxapps/docs/guides/general/storage.mdx renamed to apps/docs/editor/collaboration/storage.mdx apps/docs/guides/general/storage.mdx renamed to apps/docs/editor/collaboration/storage.mdx

@@ -361,7 +361,7 @@ new SuperDoc({
 ```
 
 <Note>
-  Bring your own provider. SuperDoc handles the editor UI, while your app controls the proofing engine or API. See [Proofing](/guides/general/proofing) and [Custom proofing provider](/guides/general/custom-proofing-provider).
+  Bring your own provider. SuperDoc handles the editor UI, while your app controls the proofing engine or API. See [Proofing](/editor/proofing/overview) and [Custom proofing provider](/editor/proofing/custom-provider).
 </Note>
 
 <Info>

…ocs/guides/general/stable-navigation.mdx apps/docs/editor/custom-ui/navigation.mdxapps/docs/guides/general/stable-navigation.mdx renamed to apps/docs/editor/custom-ui/navigation.mdx apps/docs/guides/general/stable-navigation.mdx renamed to apps/docs/editor/custom-ui/navigation.mdx

@@ -858,4 +858,4 @@ When `passwordPrompt` is enabled, recoverable encryption errors are intercepted
 When multiple encrypted documents are loaded, the password prompt queues one dialog at a time in FIFO order. After the user submits or cancels for one document, the next dialog appears.
 ## Styling
 
-Background, shadow, border radius, padding, and edge offset are all customizable via `--sd-ui-surface-*` and `--sd-ui-floating-*` CSS variables. Find/replace controls use `--sd-ui-find-replace-*`, and search highlight colors use `--sd-ui-search-match-bg` plus `--sd-ui-search-match-active-bg`. See the full token table in [Custom themes](/guides/general/custom-themes#surfaces).
+Background, shadow, border radius, padding, and edge offset are all customizable via `--sd-ui-surface-*` and `--sd-ui-floating-*` CSS variables. Find/replace controls use `--sd-ui-find-replace-*`, and search highlight colors use `--sd-ui-search-match-bg` plus `--sd-ui-search-match-active-bg`. See the full token table in [Custom themes](/editor/theming/custom-themes#surfaces).