Align docs with open source edition wording

[hauptmedia]

Summary

• remove Community Edition wording from the Docker image documentation
• replace commercial/core-product wording with explicit open-source and no-separate-editions language
• document the diagnostics edition field as a legacy compatibility value that reports community
• remove the license-key sample from the diagnostics example
• remove license-key permission rows from the system permissions documentation
• fix the Docker run example so the container name and -p option are separated correctly
• fix an invalid sample timestamp and a small grammar issue in the same diagnostics section

Verification

• rg -n -i "enterprise edition|commercial Operaton|commercial offering|commercial product|community edition|license key|license-key|Get License Key|Set License Key|Delete License Key" docs src README.md docusaurus.config.ts package.json now only returns historical Camunda 7 Community Edition release-note references, not Operaton edition or license-key wording
• git diff --check
• npm run build succeeds; it reports the known pre-existing Docusaurus link/anchor warnings addressed by follow-up docs quality PRs

References checked:

• https://github.com/operaton/operaton/blob/main/engine/src/main/java/org/operaton/bpm/engine/impl/util/ProcessEngineDetails.java
• https://github.com/operaton/operaton/blob/main/engine/src/main/java/org/operaton/bpm/engine/impl/util/ParseUtil.java
• https://github.com/operaton/operaton/blob/main/engine/src/test/java/org/operaton/bpm/engine/test/api/mgmt/ManagementServiceGetTelemetryDataTest.java