v3: keep pasted description images out of the dump kind and the card teasers

The dump modal's window-level paste listener looked at the clipboard files
before it looked at the event target, so an image pasted into the "Why?"
field was claimed twice: the editor uploaded it as an inline attachment,
and the modal switched itself to file mode with that same image as the
dump. Writing a URL dump with an illustrated description was impossible.
The target guard that already existed for text pastes now runs first and
covers files too — fields own their paste, and the URL input keeps its own
handler for the image-to-file-dump shortcut. Pasting onto the modal body,
where nothing else is listening, still starts a file dump.

Card teasers are line-clamped boxes, which an embedded image blows apart.
Inline markdown — the mode the dump and journal cards already ask for —
now drops img nodes, so a description image shows up on the detail page
and nowhere else.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TiAPtJZeCYYk8rKehtLUQU

src/components/Markdown.tsx

@@ -16,10 +16,10 @@ function preprocessMentions(text: string): string {
   return text.replace(/(?<![[(])@([\w]+)/g, "[@$1](/users/$1)");
 }
 
-// Static components object — defined once at module scope to avoid recreation on every render
-const MARKDOWN_COMPONENTS: React.ComponentProps<
-  typeof ReactMarkdown
->["components"] = {
+type Components = React.ComponentProps<typeof ReactMarkdown>["components"];
+
+// Static components objects — defined once at module scope to avoid recreation on every render
+const MARKDOWN_COMPONENTS: Components = {
   a: ({ href, children: linkChildren }) => {
     if (href?.startsWith("/users/")) {
       return <Link to={href}>{linkChildren}</Link>;
@@ -32,6 +32,14 @@ const MARKDOWN_COMPONENTS: React.ComponentProps<
   },
 };
 
+// Inline renderings are line-clamped teasers inside cards, where an embedded
+// image blows the layout apart. Drop images there — the full description is
+// one click away on the detail page.
+const INLINE_MARKDOWN_COMPONENTS: Components = {
+  ...MARKDOWN_COMPONENTS,
+  img: () => null,
+};
+
 export function Markdown(
   { children, className, inline = false }: MarkdownProps,
 ) {
@@ -45,7 +53,9 @@ export function Markdown(
     >
       <ReactMarkdown
         remarkPlugins={REMARK_PLUGINS}
-        components={MARKDOWN_COMPONENTS}
+        components={inline
+          ? INLINE_MARKDOWN_COMPONENTS
+          : MARKDOWN_COMPONENTS}
       >
         {processed}
       </ReactMarkdown>