docs: Update thread id instructions to use uuid7 (#3423)

## Overview
CC @agola11 

## Type of change

**Type:** [Replace with: New documentation page / Update existing
documentation / Fix typo/bug/link/formatting / Remove outdated content /
Other]

## Related issues/PRs
<!--
Link to related issues, feature PRs, or discussions (if applicable)

To automatically close an issue when this PR is merged, use closing
keywords:
- "closes #123" or "fixes #123" or "resolves #123"

For regular references without auto-closing, just use:
- "#123" or "See issue #123"

Examples:
- closes #456 (will auto-close issue #456 when PR is merged)
- See #789 for context (will reference but not auto-close issue #789)
-->
- GitHub issue:
- Feature PR:

<!-- For LangChain employees, if applicable: -->
- Linear issue:
- Slack thread:

## Checklist
<!-- Put an 'x' in all boxes that apply -->
- [x] I have read the [contributing guidelines](README.md), including
the [language
policy](https://docs.langchain.com/oss/python/contributing/overview#language-policy)
- [x] I have tested my changes locally using `docs dev`
- [x] All code examples have been tested and work correctly
- [x] I have used **root relative** paths for internal links
- [x] I have updated navigation in `src/docs.json` if needed

(Internal team members only / optional): Create a preview deployment as
necessary using the [Create Preview Branch
workflow](https://github.com/langchain-ai/docs/actions/workflows/create-preview-branch.yml)

## Additional notes
<!-- Any other information that would be helpful for reviewers -->

Author: jacoblee93

src/langsmith/query-threads.mdx

@@ -18,26 +18,38 @@ The SDK exposes two methods for working with threads:
 
 Each run you create can carry a `thread_id` in its metadata. LangSmith uses this to group runs into threads. The backend looks for `thread_id` in `metadata` (falling back to `session_id` or `conversation_id`).
 
+<Note>
+We recommend using **UUID v7** thread IDs. UUIDv7 embeds a timestamp, which preserves correct time-ordering of threads. The LangSmith SDK exports a uuid7 helper (Python v0.4.43+, JS v0.3.80+):
+
+- **Python**: `from langsmith import uuid7`
+- **JS/TS**: `import { uuid7 } from 'langsmith'`
+</Note>
+
 If you're using a [tracing integration](/langsmith/integrations), pass `thread_id` in the run metadata:
 
 <CodeGroup>
 
 ```python Python
-from langsmith import traceable
+from langsmith import traceable, uuid7
+
+THREAD_ID = str(uuid7())
 
-@traceable(metadata={"thread_id": "conv-abc123"})
+@traceable(metadata={"thread_id": THREAD_ID})
 def my_agent(user_message: str) -> str:
     ...
 ```
 
 ```typescript TypeScript
 import { traceable } from "langsmith/traceable";
+import { uuid7 } from "langsmith";
+
+const THREAD_ID = uuid7();
 
 const myAgent = traceable(
   async (userMessage: string) => {
     // ...
   },
-  { metadata: { thread_id: "conv-abc123" } }
+  { metadata: { thread_id: THREAD_ID } }
 );
 ```
 

src/langsmith/threads.mdx

@@ -15,7 +15,14 @@ To associate traces together, you need to pass in a special `metadata` key where
 - `thread_id`
 - `conversation_id`
 
-The value can be any string you want, but we recommend using UUIDs, such as `f47ac10b-58cc-4372-a567-0e02b2c3d479`. Check out [Add metadata and tags to traces](/langsmith/add-metadata-tags) for instructions.
+The value can be any string you want, but we recommend using **UUID v7** thread IDs.
+
+The LangSmith SDK exports a uuid7 helper (Python v0.4.43+, JS v0.3.80+):
+
+- **Python**: `from langsmith import uuid7`
+- **JS/TS**: `import { uuid7 } from 'langsmith'`
+
+Check out [Add metadata and tags to traces](/langsmith/add-metadata-tags) for instructions.
 
 <Warning>
 **Important:** To ensure filtering and token counting work correctly across your entire thread, you must set the thread metadata (`session_id`, `thread_id`, or `conversation_id`) on **all runs**, including child runs within a trace.
@@ -44,15 +51,15 @@ from dotenv import load_dotenv
 load_dotenv()
 
 import openai
-from langsmith import traceable, Client
+from langsmith import traceable, Client, uuid7
 from langsmith.wrappers import wrap_openai
 
 # Initialize clients
 langsmith_client = Client()
 client = wrap_openai(openai.Client())
 
 # Configuration
-THREAD_ID = "thread-id-1"
+THREAD_ID = str(uuid7())
 
 # Using a local directory to store thread history. For production use, use a persistent storage solution.
 THREADS_DIR = os.path.join(os.path.dirname(__file__), "threads")
@@ -115,6 +122,7 @@ import * as dotenv from "dotenv";
 import OpenAI from "openai";
 import { traceable } from "langsmith/traceable";
 import { wrapOpenAI } from "langsmith/wrappers";
+import { uuid7 } from "langsmith";
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
 
@@ -125,7 +133,7 @@ dotenv.config();
 const client = wrapOpenAI(new OpenAI());
 
 // Configuration
-const THREAD_ID = "thread-id-1";
+const THREAD_ID = uuid7();
 
 // Using a local directory to store thread history. For production use, use a persistent storage solution.
 const THREADS_DIR = path.join(__dirname, "threads");