docs(ecosystem): add Walcz to contributors (#11582)

Nine commits in this repository, all merged: native Prometheus metrics for agent
chat runs (#10689), PII/audit events as a Prometheus counter (#10641), optional
Anthropic prompt-cache breakpoints (#11158), plus fixes to cloud-proxy, the agent
UI and the Python backend.

The author's public GitHub profile names the employer, which is the evidence this
file asks for. Counts verified with the GitHub commit search API on 2026-08-18.

Placed by commit count, between Spectro Cloud and VictoriaMetrics.

Signed-off-by: Stefan Walcz <stefan.walcz@walcz.de>

Author: walcz-de

website/data/ecosystem.yaml

@@ -26,6 +26,7 @@ contributors:
   companies:
     - { name: "Microsoft",       people: 3, commits: 20 }
     - { name: "Spectro Cloud",   people: 3, commits: 11 }
+    - { name: "Walcz",           people: 1, commits: 9 }
     - { name: "VictoriaMetrics", people: 1, commits: 5 }
     - { name: "Acronis",         people: 1, commits: 5 }
     - { name: "BearingPoint",    people: 1, commits: 4 }