docs(desktop): correct local-file privacy, update, and download-origin wording

Author: waleedlatif1

README.md

@@ -36,7 +36,7 @@ Open [http://localhost:3000](http://localhost:3000)
 
 <a href="https://sim.ai/api/desktop/update/download" target="_blank" rel="noopener noreferrer"><img src="https://img.shields.io/badge/Download-macOS-3B3B3B?logo=apple&logoColor=white&labelColor=1A1A1A" alt="Download Sim for macOS"></a>
 
-Signed and notarized, universal for Apple Silicon and Intel, macOS 12+. The link always resolves to the newest release — every Sim deployment serves it at `/api/desktop/update/download`, so a self-hosted install points at its own. See the [desktop docs](https://docs.sim.ai/desktop).
+Signed and notarized, universal for Apple Silicon and Intel, macOS 12+. That link is never version-pinned — it resolves to the newest release at request time, so it does not need updating. It resolves against sim.ai; a self-hosted install serves the same endpoint on its own origin, so use `https://<your-sim-url>/api/desktop/update/download` to get the build your deployment offers. See the [desktop docs](https://docs.sim.ai/desktop).
 
 <p align="center">
   <img src="apps/sim/public/static/readme-platform.png" alt="The Sim platform — chat on the left, the visual workflow builder on the right" width="100%"/>

apps/docs/content/docs/desktop/index.mdx

@@ -23,9 +23,9 @@ Sim Desktop is the macOS app for your Sim workspace. Everything the web app does
 One universal build runs natively on both Apple Silicon and Intel Macs. It is signed and notarized by Sim, so Gatekeeper accepts it with no override.
 
 <Callout type="info">
-  That link always resolves to the newest release — it is a redirect your Sim deployment resolves at request time, not a version-pinned file. Bookmark it, share it, or put it in an MDM policy and it stays correct across every release.
+  That link is never version-pinned — it is a redirect resolved at request time, so it always lands on the newest release. Bookmark it, share it, or put it in an MDM policy and it stays correct across every release.
 
-  Every Sim deployment serves it at `/api/desktop/update/download`. On a self-hosted install, use your own origin: `https://sim.example.com/api/desktop/update/download`.
+  It resolves against sim.ai. Every Sim deployment serves the same endpoint on its own origin, so if you self-host, use yours — `https://sim.example.com/api/desktop/update/download` — and you get the build your deployment offers rather than the one sim.ai does.
 </Callout>
 
 To install a specific version instead of the newest one, pick it from [the releases page](https://github.com/simstudioai/sim/releases) and download that release's `Sim-<version>-universal.dmg`.
@@ -68,13 +68,17 @@ Fresh installs open sim.ai. To use your own deployment, choose **Sim → Server
 
 - **A built-in browser.** A real browser inside the app, with its own tabs, saved passwords, and sessions. Chat can drive it — sign in once and your agents work on the sites you are already signed into.
 - **A built-in terminal.** Real shell sessions in a panel next to Chat, with tmux and shell integration, that Chat can run commands in.
-- **Local folder access.** When a task needs a folder on your Mac, Chat offers to open the native folder picker. The grant is read-only and revocable: agents search and read the folder through the ordinary file tools, and the files themselves are never uploaded — attach one yourself if you want that.
-- **Notifications.** A native notification when a Chat task finishes. Clicking it opens that chat.
+- **Local folder access.** When a task needs a folder on your Mac, Chat offers to open the native folder picker. The grant is read-only, scoped to the folder you picked, and revocable.
+- **Notifications.** A native notification when a Chat task finishes. Clicking it opens that chat. Tasks that end in an error, or that have another message queued behind them, do not notify.
 - **Control Center.** A menu-bar icon with your recent chats, so Sim is one click away from any app.
 - **Launch at login.** Sim starts with your Mac, and however you launch it, it opens where you left off.
 
 Both the browser and the terminal are capabilities you grant, not defaults you are stuck with — each has a single switch in settings that turns it off entirely.
 
+<Callout type="warn">
+  **What a folder grant does and does not do.** Granting a folder does not copy or upload it, and an agent cannot attach a file from it or stage one for upload — that stays a deliberate act on your part. But when an agent reads or searches inside the grant, the text it reads is a tool result, and tool results go to your Sim server and to the model exactly like anything else in the conversation. Grant folders on that basis: the file stays on your Mac, what an agent reads out of it does not.
+</Callout>
+
 ## Keyboard shortcuts
 
 These are the app's own shortcuts. The [workflow editor and table shortcuts](/keyboard-shortcuts) work the same in the app as in the browser.
@@ -131,14 +135,17 @@ The menu bar carries the rest: **Sim → Settings…** (`Cmd` + `,`), **Server
 
 ## Updates
 
-Sim updates itself. It checks the deployment it is pointed at, downloads in the background, and offers to restart — choose **Later** and the update applies the next time you quit. Nothing is ever forced mid-session. **Sim → Check for Updates…** checks immediately.
+Sim updates itself, and it checks the deployment it is pointed at rather than a global feed. With **Automatically download updates** on, it downloads in the background and offers to restart — choose **Later** and the update applies the next time you quit. With it off, **Sim → Check for Updates…** starts the download. Nothing is ever forced mid-session.
+
+A build that cannot update itself — one installed outside `/Applications`, or one not signed with a Developer ID — offers you the installer to download and replace by hand instead. That is the other reason to install to `/Applications`.
 
 Updates come from the deployment you are connected to, so a self-hosted install controls which build its own users are offered. See [Desktop App on Your Deployment](/platform/self-hosting/desktop).
 
 ## Requirements
 
 - **macOS 12 Monterey or later**, on Apple Silicon or Intel.
-- **Outbound access to your Sim deployment**, and to `github.com` for update downloads.
+- **Outbound access to your Sim deployment**, and to `github.com`, which is where installers and updates are downloaded from.
+- **If you self-host**, your Sim server needs its own outbound access to both `api.github.com`, which is what resolves *which* release to offer, and `github.com`. An allowlist carrying only `github.com` leaves the download endpoint answering `502`.
 - **A system-trusted TLS certificate**, if you self-host. The app rejects certificate errors outright and offers no override, so a private CA must be installed in the macOS keychain.
 
 <Callout>