[feature] Ship native XSD schemas in all distribution layouts

Include schema/ (conf.xsd, collection.xconf.xsd, descriptor.xsd,
controller-config.xsd, mime-types.xsd, users.xsd, server.xsd,
security-manager.xsd, expath-pkg.xsd and its extensions) in the
tarball, zip, Docker image, IzPack installer, and macOS .app bundle
as $EXIST_HOME/schema/. Also fix the "abrev" -> "abbrev" typo
in expath-pkg.xsd.

Closes #6189
Partially addresses #6008

Author: duncdrum

AGENTS.md

@@ -144,6 +144,30 @@ ANTLR generates `XQueryParser.java`, `XQueryLexer.java`, `XQueryTreeParser.java`
 | `org.exist.dom.persistent` | Persistent DOM implementation |
 | `org.exist.dom.memtree` | In-memory DOM (for constructed nodes) |
 
+### Native config schemas (`schema/`)
+
+eXist-db's own config-file XSDs (`conf.xsd`, `collection.xconf.xsd`, `descriptor.xsd`,
+`controller-config.xsd`, `mime-types.xsd`, plus `users.xsd`/`server.xsd`/`security-manager.xsd`/
+`expath-pkg.xsd` and its extensions) live in [`schema/`](schema/) at the repo root, and are shipped
+in every distribution layout as `$EXIST_HOME/schema/` — a sibling of `etc/`, `bin/`, `lib/` (tarball,
+zip, Docker image, and the IzPack installer all include it; see `exist-distribution`/`exist-docker`/
+`exist-installer`). External tools (eXide, IDE plugins) can resolve a config file's grammar from
+this fixed location instead of vendoring their own copy.
+
+- Each XSD's `xs:schema/@version` is an independent semver line — see [`schema/README.md`](schema/README.md)
+  for the versioning policy (CI enforces a version bump on any semantic schema edit, via
+  `mvn -N xml:transform@schema-governance`, see [`schema/governance.xsl`](schema/governance.xsl)).
+- `org.exist.util.SchemaVersion`'s version constants are generated at build time from the XSDs
+  themselves (`generate-sources` phase, see `exist-core/pom.xml`'s `schema-version-codegen`
+  execution and [`schema/generate-schema-version.xsl`](schema/generate-schema-version.xsl)) — never
+  hand-edit `SchemaVersion`'s constants; bump the XSD's `xs:schema/@version` instead and the
+  constant follows automatically on the next build.
+- The 5 canonical instances (the files `pom.xml`'s `validate-canonical-instances` execution
+  validates on every `mvn validate`) are the only ones checked for drift; the ~39 test/sample
+  fixture copies scattered across module test resources (e.g. `extensions/*/src/test/resources*/conf.xml`)
+  are intentionally hand-trimmed per-module subsets, not literal copies — don't try to regenerate
+  them from canonical.
+
 ### Adding a new `fn:` function
 
 1. Create the class in `org.exist.xquery.functions.fn` extending `BasicFunction`

exist-distribution/pom.xml

@@ -516,12 +516,21 @@
                                 <mkdir dir="${assemble.dir}/etc"/>
                                 <mkdir dir="${assemble.dir}/bin"/>
                                 <mkdir dir="${assemble.dir}/logs"/>
+                                <mkdir dir="${assemble.dir}/schema"/>
 
                                 <!-- copy configuration files -->
                                 <copy todir="${assemble.dir}/etc">
                                     <fileset dir="${project.basedir}/src/main/config"/>
                                 </copy>
 
+                                <!-- copy native XML schemas (#6189): $EXIST_HOME/schema/, sibling to etc/ -->
+                                <copy todir="${assemble.dir}/schema">
+                                    <fileset dir="${project.basedir}/../schema">
+                                        <exclude name="*.md"/>
+                                        <exclude name="governance.xsl"/>
+                                    </fileset>
+                                </copy>
+
                                 <macrodef name="copy-script">
                                     <attribute name="src"/>
                                     <attribute name="dest"/>

exist-distribution/src/main/config/conf.xml

@@ -58,7 +58,7 @@
         - http://exist-db.org/exist/apps/doc/documentation.xml
 
 -->
-<exist xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../schema/conf.xsd" schemaVersion="2.1.1">
+<exist xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../schema/conf.xsd" schemaVersion="2.1.1">
 
     <!-- 
         Configures the database backend.

exist-distribution/src/main/config/descriptor.xml

@@ -7,7 +7,7 @@
 -->
 
 
-<xquery-app request-replay-log="false" filtered="true" schemaVersion="1.2.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="schema/descriptor.xsd">
+<xquery-app request-replay-log="false" filtered="true" schemaVersion="1.2.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../schema/descriptor.xsd">
     <!--
         request-replay-log: Controls whether the Server logs incoming requests
         to the file request-replay-log.txt. This is useful for reproducing eXist behaviour and

exist-docker/src/assembly/dist-assembly-docker.xml

@@ -37,6 +37,7 @@
                 <include>autodeploy/**</include>
                 <include>etc/**</include>
                 <include>logs/**</include>
+                <include>schema/**</include>
                 <include>LICENSE</include>
             </includes>
         </fileSet>

exist-docker/src/main/resources-filtered/Dockerfile

@@ -28,6 +28,7 @@ COPY autodeploy /exist/autodeploy
 COPY etc /exist/etc
 COPY lib /exist/lib
 COPY logs /exist/logs
+COPY schema /exist/schema
 
 
 # Build-time metadata as defined at http://label-schema.org

exist-docker/src/main/resources-filtered/Dockerfile-DEBUG

@@ -30,6 +30,7 @@ COPY autodeploy /exist/autodeploy
 COPY etc /exist/etc
 COPY lib /exist/lib
 COPY logs /exist/logs
+COPY schema /exist/schema
 
 # Build-time metadata as defined at http://label-schema.org
 # and used by autobuilder @hooks/build

exist-installer/src/main/izpack/install.xml

@@ -156,6 +156,7 @@
             </fileset>
             <fileset targetdir="$INSTALL_PATH/etc" dir="etc"/>
             <fileset targetdir="$INSTALL_PATH/lib" dir="lib"/>
+            <fileset targetdir="$INSTALL_PATH/schema" dir="schema"/>
             <fileset os="windows" targetdir="$INSTALL_PATH/lib" dir="@{izpack.resources.target}">
                 <include name="icon.ico"/>
             </fileset>

exist-jetty-config/src/main/resources/webapp/WEB-INF/catalog.xml

@@ -7,7 +7,16 @@
 
 	<!-- eXist-db internals entries -->
     <uri name="http://exist-db.org/collection-config/1.0" uri="../../../schema/collection.xconf.xsd"/>
-	
+    <uri name="http://exist.sourceforge.net/NS/exist" uri="../../../schema/controller-config.xsd"/>
+    <!-- conf.xml/descriptor.xml/mime-types.xml have no target namespace, so they're keyed by
+         the literal schemaLocation hint's suffix rather than a namespace URI. systemSuffix
+         matches regardless of how many ../ precede it, so this resolves correctly both for the
+         canonical templates (../schema/conf.xsd from etc/) and for the many test/sample
+         instance copies scattered across modules with differing relative depths. -->
+    <systemSuffix systemIdSuffix="schema/conf.xsd" uri="../../../schema/conf.xsd"/>
+    <systemSuffix systemIdSuffix="schema/descriptor.xsd" uri="../../../schema/descriptor.xsd"/>
+    <systemSuffix systemIdSuffix="schema/mime-types.xsd" uri="../../../schema/mime-types.xsd"/>
+
 	<!-- W3C XHTML DTD entries --> 
 
 	<public publicId="-//W3C//DTD XHTML 1.0 Strict//EN" uri="entities/xhtml1-strict.dtd"/> 

exist-jetty-config/src/main/resources/webapp/WEB-INF/controller-config.xml

@@ -6,7 +6,7 @@
   ++ The order of elements within this configuration file is significant.
 -->
 <configuration xmlns="http://exist.sourceforge.net/NS/exist" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-  xsi:schemaLocation="http://exist.sourceforge.net/NS/exist file:../../schema/controller-config.xsd" schemaVersion="1.1.1">
+  xsi:schemaLocation="http://exist.sourceforge.net/NS/exist file:../../../schema/controller-config.xsd" schemaVersion="1.1.1">
 
   <!-- Webstart servlet -->
   <forward pattern="/webstart" servlet="jnlp"/>