Remove stale Gatekeeper warning from README

DMGs are notarized and stapled automatically now, so the workaround
steps no longer apply. Also corrected the minimum macOS requirement
to match the actual deployment target (26.2, not 14.0).

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

README.md

@@ -123,28 +123,10 @@ Download the latest release from the [Releases page](https://gitlab.pm/rune/oai-
 3. Eject the DMG
 4. Launch oAI from Applications or Spotlight
 
-### First Launch - Gatekeeper Warning
-
-oAI is **signed by the developer** but has **not yet been notarized by Apple**. Notarization is Apple's automated malware scan - the app itself is safe, but macOS Gatekeeper may block it on first launch with a message saying the app "cannot be opened because the developer cannot be verified."
-
-To open the app, you have two options:
-
-**Option A - Right-click to open (quickest):**
-1. Right-click (or Control-click) `oAI.app` in Applications
-2. Select **Open** from the context menu
-3. Click **Open** in the dialog that appears
-4. After doing this once, the app opens normally from then on
-
-**Option B - Remove the quarantine flag via Terminal:**
-
-```bash
-xattr -dr com.apple.quarantine /Applications/oAI.app
-```
-
-This command removes the quarantine attribute that macOS attaches to files downloaded from the internet. The `-d` flag deletes the attribute, `-r` applies it recursively to the app bundle. Once removed, macOS no longer blocks the app from launching.
+Release DMGs are signed and notarized by Apple, so oAI opens normally on first launch with no Gatekeeper warning.
 
 ### Requirements
-- macOS 14.0 (Sonoma) or later
+- macOS 26.2 or later
 - An API key for at least one supported provider (OpenRouter, Anthropic, OpenAI, or Google), or Ollama running locally
 
 ## Configuration