Add kubernetes test results of v1.0.0-beta2 at 10000 concurrency

[UdeshAthukorala]

Adds the Azure AKS result for Thunder 1.0.0-beta2 at 10000 concurrent users, in the same layout as
benchmarks/v0.40.0/kubernetes: a readme.md plus one CSV per scenario.

Run: pipeline build 1500, 2026-08-13, performance repo at ff7cb7e. All stores on Postgres with
in-memory caching. Each scenario ran 15m with the first 5m discarded as warm-up.

Scenario	Throughput (req/sec)	Avg (ms)	p95 (ms)	Error %
Client Credentials	17007.43	15.54	56	0.00

The Authorization Code Grant Type and User Authentication with Credentials scenarios ran in the
same suite at this concurrency, but their error rates were too high to report as benchmarks, so
they are excluded. The readme records that they ran and were left out.

One caveat is recorded in the readme rather than left for the reader to discover: this run was
load generator bound. The JMeter client load average was 69.59 on a 64 vCore runner. In steady
state all 10000 threads were active at a 13ms average response while sustaining only about 16500
req/sec, roughly 1.65 iterations per thread per second, so the client rather than Thunder set the
ceiling. The v0.40.0 Postgres run at this concurrency has the same problem (client load average
119.78 on 72 vCores), so the two figures are not a clean comparison of server capacity.

The 797MB results.zip is not included, matching the v0.40.0 entry.