Replace GroovyPagesTemplateEngine for Zebra templates

[mdpearson]

    The four Zebra template endpoints (build, print, render, export)
    accepted any document ID and evaluated its content as Groovy code via
    GroovyPagesTemplateEngine.
    
    Three layers of fixes:
    
    1. Consolidate document lookup and type validation into
       loadZebraTemplate(), used by all four endpoints. It returns 404 for
       missing documents and throws IllegalArgumentException for documents
       whose type is not ZEBRA_TEMPLATE.
    
    2. Replace TemplateService (which wraps GroovyPagesTemplateEngine) with
       BeanPropertyTemplateService, which resolves ${...} expressions by
       delegating the full property path to Spring's BeanWrapperImpl. No
       arbitrary Groovy evaluation; unresolvable expressions throw rather
       than appearing in label output. Bracket-indexed property access is
       permitted; GSP tags and method calls are rejected with an exception.
       BeanWrapperImpl, being Spring-based, will throw if it encounters a
       Groovy safe-navigation delimiter (`?.`). That's a breaking change
       compared to the previous implementation, but I'm not sure any of our
       templates rely on this behavior. Similarly with `?:`.
    
       Property traversal is further restricted:
       - Block 'class' and 'metaClass' by name, plus Grails domain
         internals (`constraints`, `domainClass`, `errors`, `mapping`,
         `properties`).
       - Block properties of type Class, ClassLoader, MetaClass, or
         ProtectionDomain.
       - Restrict variable access to ALLOWED_BINDING_NAMES (which includes
         product and facility), rejecting names outside the set even if
         present in bindings, to prevent access to framework objects such
         as `grailsApplication`.
    
    3. Escape the ${ sequence in resolved values so property values
       containing ${...} are not re-interpreted as template expressions on
       a second pass. Literal dollar signs are preserved (e.g. "AB$202" is
       not corrupted to "AB$$202").

[Copilot]

Pull request overview

This PR hardens the Zebra template rendering endpoints by removing Groovy/GSP evaluation of user-provided document content and replacing it with a restricted, Spring BeanWrapper-based ${...} property-resolution engine, along with shared document lookup/type validation and new tests.

Changes:

• Consolidates Zebra template document loading/type validation into a shared loadZebraTemplate() helper used by all four Zebra endpoints.
• Replaces the prior Groovy/GSP-backed template rendering with BeanPropertyTemplateService using Apache Commons Text StringSubstitutor + Spring BeanWrapperImpl.
• Adds unit tests covering controller-level document type checks and service-level expression restrictions/escaping behavior.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
grails-app/controllers/org/pih/warehouse/core/DocumentController.groovy	Switches Zebra endpoints to BeanPropertyTemplateService and centralizes Zebra template loading/type validation.
grails-app/services/org/pih/warehouse/core/TemplateService.groovy	Removes the GroovyPagesTemplateEngine-backed service previously used for template evaluation.
grails-app/services/org/pih/warehouse/core/BeanPropertyTemplateService.groovy	Introduces a restricted ${...} resolver based on BeanWrapperImpl with binding/property/type constraints and value escaping.
src/test/groovy/org/pih/warehouse/core/DocumentControllerZebraTemplateSpec.groovy	Adds controller unit tests ensuring Zebra endpoints reject non-ZEBRA_TEMPLATE documents and missing IDs.
src/test/groovy/org/pih/warehouse/core/BeanPropertyTemplateServiceSpec.groovy	Adds service tests for allowed property paths, blocked expression types, blocked properties/types, and escaping behavior.
build.gradle	Adds Apache Commons Text dependency for StringSubstitutor.

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[codecov]

Codecov Report

❌ Patch coverage is 75.00000% with 15 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (release/0.9.8@405ff5d). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
.../warehouse/core/BeanPropertyTemplateService.groovy	82.22%	4 Missing and 4 partials ⚠️
...s/org/pih/warehouse/core/DocumentController.groovy	53.33%	7 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff                @@
##             release/0.9.8    #5943   +/-   ##
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  Coverage                 ?   10.63%           
  Complexity               ?     1635           
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  Files                    ?      807           
  Lines                    ?    47595           
  Branches                 ?    11248           
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  Hits                     ?     5063           
  Misses                   ?    41716           
  Partials                 ?      816           

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