feat: move revert action to message cards and improve article links

- Move the revert functionality from the journal input to individual
  message cards for better UX.
- Implement `RevealLink` component for article reveals to allow
  navigation without losing URL parameters.
- Add helper functions to format article paths and slugs into
  human-readable titles.

src/components/journal/JournalInput.tsx

@@ -20,12 +20,7 @@ import {
   Switch,
   Match,
 } from "solid-js";
-import {
-  sendMessage,
-  revertLatest,
-  canRevert,
-  useJournalStream,
-} from "../stores/journalStream";
+import { sendMessage, useJournalStream } from "../stores/journalStream";
 import {
   useJournalCompletions,
   ensureCompletions,
@@ -123,10 +118,7 @@ export const JournalInput: Component = () => {
     textareaRef?.focus();
   }
 
-  function handleRevert() {
-    revertLatest();
-  }
-
+  // ---- Completions ----
   // ---- Scroll selected completion into view ----
 
   createEffect(() => {
@@ -313,8 +305,6 @@ export const JournalInput: Component = () => {
     onCleanup(() => document.removeEventListener("mousedown", handler));
   });
 
-  const showRevert = () => canRevert() && stream.myName === "gm";
-
   // Completions placeholder — shown in the dropdown area when no matches
   function renderCompletionsDropdown() {
     const comps = currentCompletions();
@@ -414,15 +404,6 @@ export const JournalInput: Component = () => {
             <p class="text-red-500 text-xs truncate max-w-[60%]">{error()}</p>
           </Show>
           <div class="flex items-center gap-1 ml-auto">
-            <Show when={showRevert}>
-              <button
-                onClick={handleRevert}
-                class="text-xs text-gray-400 hover:text-red-500 px-1.5 py-0.5"
-                title="Revert last message"
-              >
-                ↩
-              </button>
-            </Show>
             <button
               onClick={handleSend}
               disabled={sending() || !text().trim()}