Square off the rail header and add a back button

The rail header now sits in the standard 64px row with a hairline under
it, matching the pane headers, and shows the full logo off the chat
pages instead of the bare stone. A back button joins the conversation
and settings headers (workspace pages only for the conversation). The
rail's own back link and the dividers around it are switched off for now.

Also renames the bot and workspace Delete group to Danger Zone, lifts the
step budget to 50, and lets Logo render without its home link.

src/functions/backend/storage/resolve-storage-path.ts

@@ -3,6 +3,8 @@ import path from "node:path";
 import { AppData } from "@/src/data/app-data";
 import AppError from "@/src/utils/app-error";
 
+const empty_folder_text = `Empty Folder`;
+
 type Params = {
     /**
      * The volume's absolute root (`resolveStorageSpec`'s `root`), already
@@ -48,7 +50,10 @@ export type ResolvedStoragePath = {
  * the bot's tools); a caller that needs an existing file checks it
  * afterwards.
  */
-export default function resolveStoragePath({ root, path: requested }: Params): ResolvedStoragePath {
+export default function resolveStoragePath({
+    root,
+    path: requested,
+}: Params): ResolvedStoragePath {
     const resolved_root = path.resolve(root);
     const raw = (requested || "").trim().replace(/\\/g, "/");
 
@@ -57,19 +62,26 @@ export default function resolveStoragePath({ root, path: requested }: Params): R
     }
 
     if (raw.startsWith("/") || /^[a-zA-Z]:/.test(raw)) {
-        throw new AppError(`Use a path inside the folder, not an absolute one.`);
+        throw new AppError(
+            `Use a path inside the folder, not an absolute one.`,
+        );
     }
 
-    const segments = raw.split("/").map((segment) => segment.trim()).filter(Boolean);
+    const segments = raw
+        .split("/")
+        .map((segment) => segment.trim())
+        .filter(Boolean);
 
     for (const segment of segments) {
         if (segment == "." || segment == "..") {
-            throw new AppError(`That path isn't valid: it must stay inside the folder.`);
+            throw new AppError(empty_folder_text);
         }
     }
 
     if (segments.length > AppData.BotFilePathMaxDepth) {
-        throw new AppError(`That path is too deep: at most ${AppData.BotFilePathMaxDepth} folders.`);
+        throw new AppError(
+            `That path is too deep: at most ${AppData.BotFilePathMaxDepth} folders.`,
+        );
     }
 
     const relative = segments.join("/");
@@ -81,7 +93,7 @@ export default function resolveStoragePath({ root, path: requested }: Params): R
     const absolute = path.join(resolved_root, ...segments);
 
     if (!isInsideRoot({ root: resolved_root, absolute })) {
-        throw new AppError(`That path isn't valid: it must stay inside the folder.`);
+        throw new AppError(empty_folder_text);
     }
 
     guardRealPath({ root: resolved_root, absolute });
@@ -99,7 +111,9 @@ export default function resolveStoragePath({ root, path: requested }: Params): R
  * symlink (or any other reason).
  */
 function guardRealPath({ root, absolute }: { root: string; absolute: string }) {
-    const real_root = existsSync(root) ? realpathSync(root) : path.resolve(root);
+    const real_root = existsSync(root)
+        ? realpathSync(root)
+        : path.resolve(root);
     let probe = absolute;
 
     while (!existsSync(probe)) {
@@ -113,16 +127,25 @@ function guardRealPath({ root, absolute }: { root: string; absolute: string }) {
     const real_probe = realpathSync(probe);
 
     if (!isInsideRoot({ root: real_root, absolute: real_probe })) {
-        throw new AppError(`That path isn't valid: it must stay inside the folder.`);
+        throw new AppError(empty_folder_text);
     }
 }
 
 /**
  * Whether a path is inside a root, before it exists.
  */
-export function isInsideRoot({ root, absolute }: { root: string; absolute: string }) {
+export function isInsideRoot({
+    root,
+    absolute,
+}: {
+    root: string;
+    absolute: string;
+}) {
     const resolved_root = path.resolve(root);
     const resolved = path.resolve(absolute);
 
-    return resolved == resolved_root || resolved.startsWith(`${resolved_root}${path.sep}`);
+    return (
+        resolved == resolved_root ||
+        resolved.startsWith(`${resolved_root}${path.sep}`)
+    );
 }