docs(user): add breaking change documentation for axios

docs/User Guide/User Guide/Scripting/Breaking changes/v0.102.0 Upgrade to jQuery.0.0.md

@@ -1,6 +1,4 @@
-# Breaking changes
-## v0.102.0: Upgrade to jQuery 4.0.0
-
+# v0.102.0: Upgrade to jQuery 4.0.0
 jQuery 4 removes legacy browser support (such as IE11 support), but it also removes some APIs that are considered deprecated such as:
 
 > `jQuery.isArray`, `jQuery.parseJSON`, `jQuery.trim`, `jQuery.type`, `jQuery.now`, `jQuery.isNumeric`, `jQuery.isFunction`, `jQuery.isWindow`, `jQuery.camelCase`, `jQuery.nodeName`, `jQuery.cssNumber`, `jQuery.cssProps`, and `jQuery.fx.interval`.

docs/User Guide/User Guide/Scripting/Breaking changes/v0.103.0 Removal of axios.md

@@ -0,0 +1,44 @@
+# v0.103.0: Removal of axios
+The `api.axios` library has been removed from the backend scripting API.
+
+Axios was marked as deprecated at least since April 2024 in favor of the native `fetch()` API, which is available in both browser and Node.js environments. After two years of deprecation, the library was removed following the [March 2026 npm supply chain compromise](https://www.malwarebytes.com/blog/news/2026/03/axios-supply-chain-attack-chops-away-at-npm-trust), where attackers published malicious versions that deployed a remote access trojan. The Trilium's main developer almost got compromised, but `pnpm` not trusting unknown post-install scripts successfully avoided that.
+
+Scripts that attempt to use `api.axios` will now throw an error with migration instructions.
+
+## Migration
+
+Replace `api.axios` calls with the native `fetch()` API.
+
+### `GET` calls
+
+Before (Axios):
+
+```javascript
+const response = await api.axios.get('https://api.example.com/data');
+const data = response.data;
+```
+
+After (`fetch`):
+
+```javascript
+const response = await fetch('https://api.example.com/data');
+const data = await response.json();
+```
+
+### `POST` calls
+
+Before (Axios):
+
+```javascript
+await api.axios.post('https://api.example.com/data', { key: 'value' });
+```
+
+After (fetch):
+
+```javascript
+await fetch('https://api.example.com/data', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ key: 'value' })
+});
+```