larger token size breaks pipe

[mwfarb]

The mqtt_auth endpoint can break the return response if it is too large. The current response fails approaching 4kb. This is easiest to replicate by adding a single user to several scenes as editor above 9 scenes at the current set of token construction, and viewing a page like arenaxr.org/scenes which would list all those individual scenes in one token. Several resolutions are needed likely:

• Allow larger responses from the endpoint.
• Complete namespace access control per user, allowing more concise topic control.
• Add staff tools for namespace analysis.

30 scenes fails

[31/Dec/2024 16:15:48] "POST /user/v2/mqtt_auth HTTP/1.1" 200 11360
[31/Dec/2024 16:15:48,688] - Broken pipe from ('192.168.2.14', 44154)

10 scenes fails

[31/Dec/2024 20:07:19] "POST /user/v2/mqtt_auth HTTP/1.1" 200 3970
[31/Dec/2024 20:07:19,993] - Broken pipe from ('192.168.2.14', 44868)

9 scenes succeeds

[31/Dec/2024 20:10:27] "POST /user/v2/mqtt_auth HTTP/1.1" 200 3714