Add Shared Media drawer and harden same-room navigation.

Widen the media panel, support skinny full-page mode, keep jump-to-latest and return-to-previous reliable, and stop same-room event jumps from remounting the outlet or yanking the sidebar.

src/app/components/message/Reaction.css.ts

@@ -53,6 +53,17 @@ export const Reaction = style([
   },
 ]);
 
+export const ReactionText = style([
+  DefaultReset,
+  {
+    minWidth: 0,
+    maxWidth: toRem(150),
+    display: 'inline-flex',
+    alignItems: 'center',
+    lineHeight: toRem(20),
+  },
+]);
+
 export const ReactionStack = style([
   DefaultReset,
   {
@@ -66,7 +77,7 @@ export const ReactionStack = style([
   },
 ]);
 
-export const ReactionText = style([
+export const ReactionSticker = style([
   DefaultReset,
   {
     minWidth: 0,
@@ -77,11 +88,6 @@ export const ReactionText = style([
     lineHeight: toRem(20),
     gridArea: '1 / 1',
     transformOrigin: 'center center',
-    // Fan each stacked copy so count>1 reads as multiple stickers
-    transform: `translate(
-      calc(var(--sticker-i, 0) * 7px - 2px),
-      calc(var(--sticker-i, 0) * -5px)
-    ) rotate(calc((var(--sticker-i, 0) - 1) * 12deg))`,
   },
 ]);