fix: cross-Boot-version autoconfiguration and CI-friendly version resolution

- OrdoJdbcAutoConfiguration: use string-based @AutoConfigureAfter(name = ...)
  to reference both Spring Boot 3.x and 4.x DataSource/Flyway autoconfiguration
  classes, since Boot 4 relocated these to dedicated modules.
- flatten-maven-plugin: switch flattenMode from resolveCiFriendliesOnly to
  defaults so inter-module dependency versions are fully resolved (not just
  the project's own <version>) when installed, fixing dependency resolution
  for external consumers.
- Align sibling-module dependency versions to use \ consistently.
- Ignore generated .flattened-pom.xml files.

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>com.jetlumen</groupId>
     <artifactId>ordo</artifactId>
-    <version>1.0-SNAPSHOT</version>
+    <version>${revision}</version>
 
     <packaging>pom</packaging>
 
@@ -22,6 +22,7 @@
     </modules>
 
     <properties>
+        <revision>0.0.1-SNAPSHOT</revision>
         <maven.compiler.source>21</maven.compiler.source>
         <maven.compiler.target>21</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -63,6 +64,44 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>3.5.2</version>
             </plugin>
+            <plugin>
+                <!--
+                    Resolves ${revision} and inter-module dependency versions before the
+                    POM is installed/deployed, so consumers outside this reactor (e.g.
+                    rhizome) get concrete versions instead of unresolved placeholders.
+
+                    flattenMode=resolveCiFriendliesOnly only resolves the revision/sha1/
+                    changelist properties inside <version>/<parent><version> and leaves
+                    everything else (including <dependency><version>${revision}</version>)
+                    untouched - that mode is NOT sufficient here. "defaults" performs full
+                    dependency resolution (pulling exact versions from dependencyManagement
+                    and interpolating all properties), producing a self-contained pom for
+                    each module with no leftover placeholders.
+                -->
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>flatten-maven-plugin</artifactId>
+                <version>1.6.0</version>
+                <configuration>
+                    <updatePomFile>true</updatePomFile>
+                    <flattenMode>defaults</flattenMode>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>flatten</id>
+                        <phase>process-resources</phase>
+                        <goals>
+                            <goal>flatten</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>flatten.clean</id>
+                        <phase>clean</phase>
+                        <goals>
+                            <goal>clean</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>