[PLAT-8912] Document property key policies

[MadisonEhlers-Vertex]

Summary

• Add a developer guide for property key policy allowlists and denylists.
• Document the PR #766 /keys API contract for creating policies, adding keys, and binding a policy to a scene stream key.
• Add the guide to API Advanced Steps navigation.

Validation

• Docusaurus production build succeeds.
• Platdev acceptance test: created an allowlist policy, added and retrieved the part-number and material keys, confirmed idempotent upsert, and created a stream key that returned the selected propertyKeyPolicyId.
• Deleted the temporary stream key and policy after verification.

[sksizer]

This may be pedantic - but just an FYI this is the one entry in the left hand navigation that requires two lines. maybe we throw in a style to indent the second line or something:

[sksizer]

A couple minor nits/questions but no blockers

[MadisonEhlers-Vertex]

This may be pedantic - but just an FYI this is the one entry in the left hand navigation that requires two lines. maybe we throw in a style to indent the second line or something:

Good idea - I think we should rename this to "Property key policies"

[sksizer]

lgtm. One nit - I would generally prefer to keep the title as canonical source, and not have a label override in sidebar unless it was an explicit choice

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
100.0% Duplication on New Code

See analysis details on SonarQube Cloud