Feature Request: Add a Property to Disable All AI Models at Once

Context

Users often encounter confusion when setting spring.ai.model.chat=none, as they may not have considered other types of models beyond chat model.

related issues:

• https://github.com/spring-projects/spring-ai/issues/3444
• https://github.com/spring-projects/spring-ai/issues/3561

To address this, I propose introducing a spring.ai.model.all property that allows disabling all models at once.

Current Behavior

Each module needs to be disabled manually.

For example, in the case of the OpenAI module:

spring.ai.model.chat=none
spring.ai.model.audio.speech=none
spring.ai.model.audio.transcription=none
spring.ai.model.image=none
spring.ai.model.embedding=none
spring.ai.model.moderation=none

Expected Behavior

When the property spring.ai.model.all is set, all model types should be disabled.

spring.ai.model.all=none

Start by tracing how the existing spring.ai.model.* properties are handled across the model modules, using the listed property names as entry points. Verify that setting spring.ai.model.all=none disables chat, audio, image, embedding, and moderation models, and add or update coverage for that behavior.