feat: enrich AgentInstanceResponse with version/capabilities, add password reset endpoint

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cameleer3-server-app/src/main/java/com/cameleer3/server/app/controller/UserAdminController.java

@@ -1,5 +1,6 @@
 package com.cameleer3.server.app.controller;
 
+import com.cameleer3.server.app.dto.SetPasswordRequest;
 import com.cameleer3.server.core.admin.AuditCategory;
 import com.cameleer3.server.core.admin.AuditResult;
 import com.cameleer3.server.core.admin.AuditService;
@@ -12,6 +13,7 @@ import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.servlet.http.HttpServletRequest;
+import jakarta.validation.Valid;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.DeleteMapping;
@@ -172,6 +174,18 @@ public class UserAdminController {
         return ResponseEntity.noContent().build();
     }
 
+    @PostMapping("/{userId}/password")
+    @Operation(summary = "Reset user password")
+    @ApiResponse(responseCode = "204", description = "Password reset")
+    public ResponseEntity<Void> resetPassword(
+            @PathVariable String userId,
+            @Valid @RequestBody SetPasswordRequest request,
+            HttpServletRequest httpRequest) {
+        userRepository.setPassword(userId, passwordEncoder.encode(request.password()));
+        auditService.log("reset_password", AuditCategory.USER_MGMT, userId, null, AuditResult.SUCCESS, httpRequest);
+        return ResponseEntity.noContent().build();
+    }
+
     public record CreateUserRequest(String username, String displayName, String email, String password) {}
     public record UpdateUserRequest(String displayName, String email) {}
 }