Chore(release): prepare 0.1.0-rc.9

[Proxicon]

Release preparation

Sets the repository-wide evaluated version to 0.1.0-rc.9 and records the release notes in docs/releases.md.

Included since rc.8

• Email Settings and Automation administration navigation consolidation (Consolidate Email Settings and Automation navigation #59, UX: consolidate Email Settings and Automation administration #58).
• Tenant-scoped administration and compact role editing (Compact role editing and restore tenant-scoped Team, Customers and SLA administration #57, Compact role editing and restore tenant-scoped Team, Customers and SLA administration #56).
• Dark/system theme first-paint correction (fix(ui): prevent light-theme flash during dark and system-mode startup #55, fix(ui): prevent light-theme flash during dark and system-mode startup #54).
• MailKit 4.18.0, MudBlazor 9.10.0, ModelContextProtocol.AspNetCore 2.2.0, NSubstitute 6.2.0, xunit.runner.visualstudio 4.0.0, and Docker CI action refreshes (Chore: Bump MailKit and MudBlazor #32-Chore(deps): bump docker/build-push-action from 6.18.0 to 7.3.0 #42).

Excluded

• SixLabors.ImageSharp 4.1.2 (Chore: Bump SixLabors.ImageSharp from 3.1.12 to 4.1.2 #35) remains excluded pending an approved Six Labors license key or license file.

Validation

• dotnet msbuild src/Helpdesk.API/Helpdesk.API.csproj -nologo -getProperty:Version → 0.1.0-rc.9
• tools/ci/validate-layout.sh
• slopwatch analyze --no-baseline --fail-on warning reported existing repository-wide findings; no baseline exists for an incremental comparison.