fix: ClickHouse auth credentials and non-fatal schema init

- Set CLICKHOUSE_USER/PASSWORD via k8s secret (fixes "disabling network
  access for user 'default'" when no password is set)
- Add clickhouse-credentials secret to CI deploy + feature branch copy
- Pass CLICKHOUSE_USERNAME/PASSWORD env vars to server pod
- Make schema initializer non-fatal so server starts even if CH is
  temporarily unavailable

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

cameleer3-server-app/src/main/java/com/cameleer3/server/app/config/ClickHouseSchemaInitializer.java

@@ -30,23 +30,27 @@ public class ClickHouseSchemaInitializer {
     }
 
     @EventListener(ApplicationReadyEvent.class)
-    public void initializeSchema() throws IOException {
-        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
-        Resource[] scripts = resolver.getResources("classpath:clickhouse/*.sql");
+    public void initializeSchema() {
+        try {
+            PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
+            Resource[] scripts = resolver.getResources("classpath:clickhouse/*.sql");
 
-        Arrays.sort(scripts, Comparator.comparing(Resource::getFilename));
+            Arrays.sort(scripts, Comparator.comparing(Resource::getFilename));
 
-        for (Resource script : scripts) {
-            String sql = script.getContentAsString(StandardCharsets.UTF_8);
-            log.info("Executing ClickHouse schema script: {}", script.getFilename());
-            for (String statement : sql.split(";")) {
-                String trimmed = statement.trim();
-                if (!trimmed.isEmpty()) {
-                    clickHouseJdbc.execute(trimmed);
+            for (Resource script : scripts) {
+                String sql = script.getContentAsString(StandardCharsets.UTF_8);
+                log.info("Executing ClickHouse schema script: {}", script.getFilename());
+                for (String statement : sql.split(";")) {
+                    String trimmed = statement.trim();
+                    if (!trimmed.isEmpty()) {
+                        clickHouseJdbc.execute(trimmed);
+                    }
                 }
             }
-        }
 
-        log.info("ClickHouse schema initialization complete ({} scripts)", scripts.length);
+            log.info("ClickHouse schema initialization complete ({} scripts)", scripts.length);
+        } catch (Exception e) {
+            log.error("ClickHouse schema initialization failed — server will continue but ClickHouse features may not work", e);
+        }
     }
 }