Completes the desktop half of the Settings Redesign Figma (TFhrx7FBh2Ue5SGH8CUeBU) that the user-settings pass left out: General, Access, Pipelines, Hooks and Sites, plus the rename, custom-label, collaborator, secret and webhook drill-downs. There was no repository settings surface in the rewrite at all, so this adds the route tree under [handle]/[repo]/settings and a Settings tab on RepoTabs. The tab is unconditional for now -- gating it needs the viewer's push access, which the repo layout load doesn't resolve yet. The sidebar card, drill-down shell and row primitives are reused from the user settings. Three of them grew to cover patterns that only appear on the repo pages: SettingsList's gap is now named in spacing units because the designs use all of 8/12/16px, SettingsRow takes a muted description, and SettingsBlock is the new title+description+action header that Access and Pipelines put above each card. Multi-line copy is passed as an array of lines rather than a string with escapes, which reads better and keeps the templates free of useless mustaches. SettingsEmpty replaces EmptyState inside settings: Figma's empty state there is a single 52px row, not the tall italic box the rest of the app uses. SettingsSaveBar factors out the Reset / "Unsaved changes" / Save trio now that General, Sites and Profile all carry it. Verified light and dark against the Figma renders; navigation, card and surface tokens plus nav width and heading size all match. Refs TAN-575. Signed-off-by: eti <eti@eti.tf>