[refactor] Set version to 0.9.0-SNAPSHOT for pre-release

Reserve 1.0.0 for first stable release from eXist-db org.
0.9.0 signals feature-complete, awaiting official adoption.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: joewiz

README.md

@@ -7,7 +7,7 @@ A standalone XAR package implementing the [EXPath Cryptographic Module](http://e
 Download the `.xar` from [Releases](https://github.com/joewiz/exist-crypto/releases) and install with the eXist-db Package Manager or the `xst` CLI:
 
 ```bash
-xst package install exist-crypto-1.0.0.xar
+xst package install exist-crypto-0.9.0-SNAPSHOT.xar
 ```
 
 ## Functions
@@ -99,7 +99,7 @@ This package is a clean-room replacement for the legacy [`expath-crypto-module`]
 1. **Install the new package** — a `pre-install.xq` script automatically detects and removes the old `expath-crypto-module` if present:
 
    ```bash
-   xst package install exist-crypto-1.0.0.xar
+   xst package install exist-crypto-0.9.0-SNAPSHOT.xar
    ```
 
    To remove the old package manually (e.g., before downloading the new one):

pom.xml

@@ -13,7 +13,7 @@
 
     <groupId>org.exist-db</groupId>
     <artifactId>exist-crypto</artifactId>
-    <version>1.0.0</version>
+    <version>0.9.0-SNAPSHOT</version>
 
     <name>EXPath Crypto Module</name>
     <description>EXPath Cryptographic Module for eXist-db: HMAC, symmetric encryption/decryption, and XML digital signatures using Java JCE</description>

xar-assembly.xml

@@ -58,7 +58,7 @@
     </components>
 
     <changelog>
-        <change xmlns="http://exist-db.org/xquery/repo" version="1.0.0">
+        <change xmlns="http://exist-db.org/xquery/repo" version="0.9.0-SNAPSHOT">
             <ul xmlns="http://www.w3.org/1999/xhtml">
                 <li>Initial release as standalone EXPath package</li>
                 <li>Functions: crypto:hash, crypto:hmac, crypto:encrypt, crypto:decrypt, crypto:generate-signature, crypto:validate-signature</li>