fix(desktop): declare katex-memo deps directly + drop per-app lockfile

katex-memo.ts (added in 112cad59b) imports hast-util-from-html-isomorphic,
hast-util-to-text, remark-math, katex, and unist-util-visit-parents but
those were never added to apps/desktop/package.json. They were silently
resolving via @streamdown/math at the workspace root, which broke the
moment `npm i --prefix apps/desktop` ran with the per-workspace lockfile
because that install only consults apps/desktop/package.json. Add them
as direct deps, plus unified/vfile/@types/hast for the type imports.

Also delete apps/desktop/package-lock.json — root package.json declares
workspaces: ["apps/*"], so npm manages all lockfile state at the root.
The stale per-app lockfile is what made `npm i --prefix apps/desktop`
diverge from the workspace install in the first place and left an empty
apps/desktop/node_modules/@assistant-ui/ stub that Vite's dep optimizer
then tried (and failed) to open at @assistant-ui/core/dist/internal.js.

apps/desktop/package.json

@@ -57,7 +57,10 @@
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "cmdk": "^1.1.1",
+    "hast-util-from-html-isomorphic": "^2.0.0",
+    "hast-util-to-text": "^4.0.2",
     "ignore": "^7.0.5",
+    "katex": "^0.16.45",
     "leva": "^0.10.1",
     "lucide-react": "^0.577.0",
     "motion": "^12.38.0",
@@ -68,18 +71,23 @@
     "react-dom": "^19.2.5",
     "react-router-dom": "^7.14.2",
     "react-shiki": "^0.9.3",
+    "remark-math": "^6.0.0",
     "shiki": "^4.0.2",
     "streamdown": "^2.5.0",
     "tailwind-merge": "^3.5.0",
     "tailwindcss": "^4.2.4",
     "tw-shimmer": "^0.4.11",
     "unicode-animations": "^1.0.3",
+    "unified": "^11.0.5",
+    "unist-util-visit-parents": "^6.0.2",
     "use-stick-to-bottom": "^1.1.4",
+    "vfile": "^6.0.3",
     "web-haptics": "^0.0.6"
   },
   "devDependencies": {
     "@eslint/js": "^9.39.4",
     "@testing-library/react": "^16.3.2",
+    "@types/hast": "^3.0.4",
     "@types/node": "^24.12.2",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",

package-lock.json

@@ -82,7 +82,10 @@
         "class-variance-authority": "^0.7.1",
         "clsx": "^2.1.1",
         "cmdk": "^1.1.1",
+        "hast-util-from-html-isomorphic": "^2.0.0",
+        "hast-util-to-text": "^4.0.2",
         "ignore": "^7.0.5",
+        "katex": "^0.16.45",
         "leva": "^0.10.1",
         "lucide-react": "^0.577.0",
         "motion": "^12.38.0",
@@ -93,18 +96,23 @@
         "react-dom": "^19.2.5",
         "react-router-dom": "^7.14.2",
         "react-shiki": "^0.9.3",
+        "remark-math": "^6.0.0",
         "shiki": "^4.0.2",
         "streamdown": "^2.5.0",
         "tailwind-merge": "^3.5.0",
         "tailwindcss": "^4.2.4",
         "tw-shimmer": "^0.4.11",
         "unicode-animations": "^1.0.3",
+        "unified": "^11.0.5",
+        "unist-util-visit-parents": "^6.0.2",
         "use-stick-to-bottom": "^1.1.4",
+        "vfile": "^6.0.3",
         "web-haptics": "^0.0.6"
       },
       "devDependencies": {
         "@eslint/js": "^9.39.4",
         "@testing-library/react": "^16.3.2",
+        "@types/hast": "^3.0.4",
         "@types/node": "^24.12.2",
         "@types/react": "^19.2.14",
         "@types/react-dom": "^19.2.3",