feat(client): feed message cells render markdown + drop selection styling

- ActivityRow: Reply/Prompt message cells now render detail through
  ReactMarkdown with a fragment <p> renderer, so bold/italic/code/links
  work while multi-paragraph messages flow inline without injecting
  visible vertical breaks. Switched the outer wrapper from span to div
  to safely host block markdown children.
- ActivityFeed.css:
  - is-message detail: white-space pre-wrap → normal so embedded '\n'
    collapses into a space (user didn't want line breaks in messages).
    Added defensive styling for code/pre/ul/ol/a/strong/em children.
  - Removed the .feed-entry.is-selected background/box-shadow/name-glow
    rules. Feed cells no longer render any blue selection marker —
    selection is conveyed by the Phaser hero halo and the PartyBar row.

Author: FulAppiOS

client/src/components/ActivityFeed.css

@@ -28,8 +28,8 @@
   transition: height 0.18s ease;
 }
 
-.activity-feed.fold-full    { height: 420px; }
-.activity-feed.fold-compact { height: 120px; }
+.activity-feed.fold-full    { height: 390px; }
+.activity-feed.fold-compact { height: 150px; }
 .activity-feed.fold-closed  { height: 32px;  }
 
 /* === Header === */
@@ -80,31 +80,6 @@
 
 .feed-spacer { flex: 1; }
 
-.feed-tabs {
-  display: flex;
-  gap: 2px;
-  background: rgba(0, 0, 0, 0.25);
-  border-radius: 4px;
-  padding: 2px;
-}
-.feed-tab {
-  padding: 3px 10px;
-  font-size: 12px;
-  color: var(--feed-pergamena);
-  opacity: 0.6;
-  border: none;
-  background: transparent;
-  border-radius: 3px;
-  cursor: pointer;
-  font-family: inherit;
-}
-.feed-tab.active {
-  background: rgba(196, 163, 90, 0.3);
-  color: #fff;
-  opacity: 1;
-  font-weight: bold;
-}
-
 .feed-fold-buttons { display: flex; gap: 4px; }
 .feed-fold-btn {
   width: 26px; height: 24px;
@@ -313,7 +288,7 @@
 .feed-detail.is-path:hover { text-decoration: underline; color: #fff; }
 .feed-detail.is-path-unresolved { color: var(--feed-path); opacity: 0.7; }
 .feed-detail.is-message {
-  white-space: pre-wrap;
+  white-space: normal;
   overflow: visible;
   text-overflow: clip;
   line-height: 1.45;
@@ -328,6 +303,40 @@
 .feed-detail.is-message::-webkit-scrollbar-thumb { background: rgba(196, 163, 90, 0.4); border-radius: 2px; }
 .feed-detail.is-message.is-reply { color: var(--feed-pergamena); }
 .feed-detail.is-message.is-prompt { color: #d8e3f2; font-style: italic; }
+/* Markdown rendering inside message cells: keep everything inline so the
+   detail flows as a single line group. `p` is already stripped via a
+   fragment renderer in ActivityRow, but guard the rest so lists/code
+   blocks don't blow up the row height. */
+.feed-detail.is-message code {
+  background: rgba(255, 255, 255, 0.08);
+  padding: 0 4px;
+  border-radius: 3px;
+  font-family: 'Fira Code', ui-monospace, monospace;
+  font-size: 0.92em;
+}
+.feed-detail.is-message pre {
+  margin: 4px 0;
+  padding: 6px 8px;
+  background: rgba(0, 0, 0, 0.3);
+  border-radius: 3px;
+  overflow-x: auto;
+  white-space: pre;
+}
+.feed-detail.is-message pre code {
+  background: transparent;
+  padding: 0;
+}
+.feed-detail.is-message ul,
+.feed-detail.is-message ol {
+  margin: 2px 0;
+  padding-left: 1.2em;
+}
+.feed-detail.is-message a {
+  color: var(--feed-path);
+  text-decoration: underline;
+}
+.feed-detail.is-message strong { color: #fff; }
+.feed-detail.is-message em { color: #d8d0b8; }
 
 /* === Group (By Agent) === */
 .feed-group {
@@ -462,28 +471,10 @@
 .feed-entry.is-highlighted.hl-agent    { border-left-color: #7ac49a;                  background: rgba(122, 196, 154, 0.08); }
 .feed-entry.is-highlighted.hl-other    { border-left-color: #888;                     background: rgba(136, 136, 136, 0.06); }
 
-.feed-entry.is-selected {
-  background: rgba(91, 163, 245, 0.1);
-  animation: feed-select-pulse 1.5s ease-in-out infinite;
-}
-.feed-entry.is-selected.is-highlighted {
-  background: rgba(91, 163, 245, 0.14);
-}
-.feed-entry.is-selected .feed-agent-name {
-  color: #FFFFFF !important;
-  text-shadow: 0 0 6px rgba(91, 163, 245, 0.9);
-}
-
-@keyframes feed-select-pulse {
-  0%, 100% { box-shadow: inset 4px 0 0 #5BA3F5, 0 0 6px rgba(91, 163, 245, 0.3); }
-  50%      { box-shadow: inset 4px 0 0 #5BA3F5, 0 0 14px rgba(91, 163, 245, 0.7); }
-}
-@media (prefers-reduced-motion: reduce) {
-  .feed-entry.is-selected {
-    animation: none;
-    box-shadow: inset 4px 0 0 #5BA3F5, 0 0 10px rgba(91, 163, 245, 0.5);
-  }
-}
+/* Selection feedback on the feed cell is intentionally absent — the hero
+   halo in Phaser and the PartyBar row already convey which agent is
+   selected, and the click target here only needs to react visually while
+   pressed (handled natively). */
 
 /* Category pill styling for agent/other/reads/messages (errors/edits/bash reuse existing) */
 .feed-pill.messages    { background: rgba(224, 138, 63, 0.15); color: #f0c99a; border-color: rgba(224, 138, 63, 0.4); }

client/src/components/ActivityRow.tsx

@@ -1,9 +1,17 @@
-import { memo, useCallback, useEffect, useState } from 'react';
+import { memo, useCallback, useEffect, useState, type ReactNode } from 'react';
+import ReactMarkdown from 'react-markdown';
 import { HERO_LABEL_COLOR, type ActivityLogEntry, type AgentState } from '../types/agent';
 import { HeroAvatar } from './HeroAvatar';
 import { isError, isPath, resolvePath, categorizeEntry } from './activityFeedUtils';
 import type { ActionFilter } from './activityFeedUtils';
 
+// Message cells render detail as markdown (bold, italic, code, links). The
+// custom `p` renderer emits a fragment so multiple paragraphs flow inline —
+// no extra vertical space, no visible paragraph breaks.
+const MD_COMPONENTS = {
+  p: ({ children }: { children?: ReactNode }) => <>{children}</>,
+};
+
 interface ActivityRowProps {
   entry: ActivityLogEntry;
   agent: AgentState | undefined;
@@ -85,7 +93,9 @@ function ActivityRowImpl({
           <span className="feed-time">{time}</span>
         </div>
         {isMessage ? (
-          <span className={`feed-detail is-message ${pillVariant}`}>{entry.detail}</span>
+          <div className={`feed-detail is-message ${pillVariant}`}>
+            <ReactMarkdown components={MD_COMPONENTS}>{entry.detail}</ReactMarkdown>
+          </div>
         ) : detailIsPath && absolute !== null ? (
           <a
             href={`vscode://file${encodeURI(absolute)}`}