docs: update B20 activation status to reflect mainnet delay

docs/base-chain/specs/upgrades/beryl/b20.mdx

@@ -8,7 +8,7 @@ B20 is the Base ecosystem's own version of [ERC-20](https://eips.ethereum.org/EI
 To deploy your first B20 token, see the [Launch a B20 Token](/get-started/launch-b20-token) quickstart.
 
 <Warning>
-B20 activation on mainnet is anticipated on **June 26, 2026 at 6pm UTC**. The Activation Registry can take up to ~1 hour to be fully enabled. [Verify the Activation Registry is enabled](/get-started/launch-b20-token#verify-the-activation-registry-is-enabled) before attempting to deploy.
+B20 mainnet activation has been delayed due to an unrelated stability incident. We're pushing back the Activation Registry enablement to ensure a smooth rollout — Sepolia and Vibenet remain on track. We'll share a revised date shortly. [Verify the Activation Registry is enabled](/get-started/launch-b20-token#verify-the-activation-registry-is-enabled) before attempting to deploy.
 </Warning>
 
 B20 supports two variants:

docs/docs.json

@@ -2,6 +2,15 @@
   "$schema": "https://mintlify.com/docs.json",
   "theme": "aspen",
   "name": "Base Documentation",
+  "banner": {
+    "content": "B20 mainnet activation has been delayed due to an unrelated stability incident. A revised date will be announced shortly. [Check activation status](/get-started/launch-b20-token#verify-the-activation-registry-is-enabled)",
+    "type": "info",
+    "dismissible": true,
+    "color": {
+      "light": "#578BFA",
+      "dark": "#578BFA"
+    }
+  },
   "colors": {
     "primary": "#0000ff",
     "light": "#578BFA",

docs/get-started/launch-b20-token.mdx

@@ -25,7 +25,7 @@ You need **Base's Foundry build** (`base-forge`, `base-cast`, [`base-anvil`](htt
 ## Verify the Activation Registry is enabled
 
 <Warning>
-**The Activation Registry must be enabled before you can deploy.** B20 activation on mainnet is anticipated on **June 26, 2026 at 6pm UTC**. After Beryl activates, the Activation Registry can take up to ~1 hour to be fully enabled. Attempting to deploy before it's ready will revert with `FeatureNotActivated`. Run the check for the variant you plan to deploy and confirm it returns `true` before proceeding:
+**B20 mainnet activation has been delayed due to an unrelated stability incident.** We're pushing back the Activation Registry enablement to ensure a smooth rollout — Sepolia and Vibenet remain on track. We'll share a revised date shortly. Attempting to deploy before it's ready will revert with `FeatureNotActivated`. Run the check for the variant you plan to deploy and confirm it returns `true` before proceeding:
 </Warning>
 
 ```bash Terminal theme={null}