no-em-dash pre-commit hook for user-facing strings, existing em-dashes rewritten

frontend/scripts/no-em-dash.ts walks src/ with the TypeScript parser and flags
an em-dash in JSX text, string literals and template text. A bare "—"
placeholder passes, separators go in no-em-dash.allow.json. The script is
identical to index's copy.

frontend/src/components/Flow/FlowDock.tsx

@@ -293,7 +293,7 @@ export function FlowDock({
           saving={saving}
           publishing={publishing}
           offline={!connected}
-          draftHint="Saved — publish to put it live"
+          draftHint="Saved. Publish to put it live"
           onPublish={onPublish}
         />
       </Dock>

frontend/src/components/Flow/FlowEditor.tsx

@@ -1139,7 +1139,7 @@ function FlowEditorInner({
       JSON.stringify({ nodes: picked, sources } satisfies NodeClipboard),
     )
     if (!stored) {
-      notify("That is too much to copy — the browser store is full.", "error")
+      notify("That is too much to copy. The browser store is full.", "error")
     }
   }, [canvasNodes, definitions, flowName, selectedId, sourceTypes])
 

frontend/src/components/Flow/FlowNode.tsx

@@ -70,7 +70,7 @@ const NODE_ICONS = {
 const STATUS_STYLES = {
   queued: {
     dot: "bg-muted-foreground",
-    label: "Queued — waiting for a machine",
+    label: "Queued, waiting for a machine",
   },
   running: { dot: "bg-primary animate-pulse", label: "Running" },
   success: { dot: "bg-status-success", label: "Last run succeeded" },
@@ -282,7 +282,7 @@ function FlowNodeComponent({ data, selected }: NodeProps) {
                   )}
                   aria-label={
                     failedEarlier
-                      ? `Failed at ${failedAt} — show the traceback`
+                      ? `Failed at ${failedAt}. Show the traceback`
                       : "Show what this node printed"
                   }
                   data-testid="node-traceback"
@@ -299,7 +299,7 @@ function FlowNodeComponent({ data, selected }: NodeProps) {
               </TooltipTrigger>
               <TooltipContent>
                 {failedEarlier
-                  ? `Failed at ${failedAt} — show the traceback`
+                  ? `Failed at ${failedAt}. Show the traceback`
                   : "Show the traceback"}
               </TooltipContent>
             </Tooltip>