link cleared sessions back to the conversation they continue

/clear starts a new claude session and the list showed it as an unrelated
conversation. claude records no parent link anywhere — not in compactMetadata,
logicalParentUuid, summary.leafUuid, the per-session slug, or the live process
registry — so infer it: a cleared transcript opens with /clear, and /clear
happens inside one process, so the parent is the conversation in the same group
that was writing to disk at the instant this one began (4ms apart, measured).

matching is on per-minute activity rather than updatedAt, because resuming a
parent moves its end time past its child's birth and lost the link entirely for
two of the three cleared sessions here. the window is symmetric because clearing
makes claude summarise the conversation it is ending, so the parent's final
record can land after the child's first. ambiguity fails closed — the wrong
parent also renames the conversation.

read-only: nothing is written back to claude's store, and an explicit title
always wins.

also: cleared sessions were titled "<command-name>/clear</command-name>" because
claude does not set isMeta on slash commands; and the chat header was hardcoded
to undefined, so it read "New chat" above every conversation you opened.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/servers/api/chat/chat.ts

@@ -10,6 +10,7 @@ import {
   deleteClaudeSession,
   renameClaudeSession,
   loadBackgroundTask,
+  claudeSessionContext,
 } from './claude-sessions';
 import {
   listOpenCodeSessions,
@@ -73,7 +74,20 @@ chatRouter.get('/sessions/:id', async (ctx) => {
   const windowed = limit != null || beforeRaw != null;
   const messages = windowed ? detail.messages.slice(start, end) : detail.messages;
 
-  return ctx.json({ ...detail, messages, total, offset: windowed ? start : 0 });
+  // The title the list shows this session under, and what it continues. Resolved against `detail.cwd`
+  // — the transcript's own directory — not the requested `cwd`, which on a deep link is still the
+  // default group and holds none of this session's neighbours. OpenCode has no lineage of its own, so
+  // it gets neither rather than a fabricated answer.
+  const context = isOpenCodeSessionId(id) ? null : claudeSessionContext(email, detail.cwd, id);
+
+  return ctx.json({
+    ...detail,
+    messages,
+    total,
+    offset: windowed ? start : 0,
+    title: context?.title ?? null,
+    continuedFrom: context?.continuedFrom ?? null,
+  });
 });
 
 // DELETE /chat/sessions/:id[?cwd=] — remove a conversation from the owning harness's store.