feat: show conversations in mobile search preview (Closes #803)

src/main.py

@@ -2778,6 +2778,32 @@ async def global_search_preview(
     return JSONResponse(preview)
 
 
+@app.get("/api/v1/repos/{owner}/{repo}/issues/{number}/preview/conversation")
+async def global_search_preview_conversation(
+    owner: str,
+    repo: str,
+    number: int = PathParam(gt=0),
+    kind: Literal["issue", "pull"] = Query(),
+    page: int | None = Query(default=None, ge=1, le=100),
+    limit: int = Query(default=20, ge=1, le=50),
+) -> JSONResponse:
+    del kind  # Issue and pull-request conversations share Gitea's issue-comments API.
+    try:
+        conversation = await asyncio.wait_for(
+            gitea_proxy.issue_conversation_page(
+                f"{owner}/{repo}", number, page, limit
+            ),
+            timeout=GLOBAL_SEARCH_TIMEOUT_SECONDS,
+        )
+    except Exception:
+        return JSONResponse(
+            {"error": "This conversation is temporarily unavailable. Please retry."},
+            status_code=503,
+            headers={"Retry-After": "1"},
+        )
+    return JSONResponse(conversation)
+
+
 @app.get("/api/v1/work-route")
 async def resolve_work_route(
     kind: Literal["issue", "pull", "review", "update"] = Query(),