feat(status): localize selection count and stage/unstage buttons

Replace hard-coded "X selected" and "Stage/Unstage X" labels in the status panel
with i18n lookups. Adds three message keys with English and German texts:
- status.selectionCount
- status.stageCount
- status.unstageCount

StatusPanel.svelte now uses t(...) with the count for the selection badge and the
stage/unstage action buttons. CHANGELOG.md was also updated (Unreleased and
recent release entries).

CHANGELOG.md

@@ -4,6 +4,180 @@ All notable user-facing changes to Gitty are documented in this file.
 
 The project uses calendar-style versions in the form `YYYY.M.PATCH`.
 
+## [Unreleased]
+
+### Added
+
+- Ctrl/Cmd + 1 to 4 switch between Dashboard, Repositories, Pull Requests,
+  and Issues & Boards.
+- Ctrl/Cmd + A selects every file in the focused status lane; Esc clears the
+  selection again.
+- Issues can be assigned to people, and labels are managed directly from the
+  Issue Center.
+
+### Changed
+
+- The description field of the Create Issue dialog uses the full comment
+  editor instead of a plain text area.
+- The help center no longer carries a "What's new" section. Release notes are
+  maintained in this file.
+
+### Fixed
+
+- Long file paths no longer displace the header controls of the file history
+  dialog.
+
+## [2026.9.8] - 2026-09-18
+
+### Added
+
+- Submodule management: submodules are listed, initialized, updated, and
+  cloned recursively, including authentication and checkout of a specific
+  submodule revision.
+- Worktrees and tags are available as collapsible panels in the left sidebar,
+  and a section menu toggles which panels are shown.
+- Individual lines can be restored from a historical commit instead of
+  restoring the whole file.
+- The branch panel supports filtering, remembers its view state, and groups
+  branches with their own accent color.
+- Pull request merges offer a merge-method selection with provider-specific
+  payloads and can delete the source branch automatically.
+- The Review Center filters by repository, and select menus show repository
+  details next to each option.
+
+### Changed
+
+- File history marks the entry that is identical to the working tree.
+- Confirmation dialogs are centralized, translated, and can carry inputs,
+  checkboxes, and multi-selection actions.
+- Left sidebar panels share one sizing and resize implementation, and global
+  scrollbar styles were consolidated.
+- Status colors, overlay tints, and theme tokens for ink and accent moved to
+  CSS variables.
+
+### Fixed
+
+- The repository selector in the tab bar shows a pointer cursor.
+
+## [2026.9.7] - 2026-09-11
+
+### Added
+
+- Pull request drafts can be generated with AI; all AI settings live on one
+  page.
+- The commit history resolves visible parents, which keeps the graph correct
+  when commits are filtered.
+
+### Changed
+
+- Dialogs share unified header chrome.
+- Provider icons were restyled and share one implementation.
+
+### Fixed
+
+- Switching to the Management view no longer opens a repository on its own.
+
+## [2026.9.6] - 2026-09-11
+
+### Added
+
+- Workspaces group repositories into sessions that can be saved, switched,
+  and managed; their UI filters persist.
+- Repository tabs can be reordered by drag and drop.
+- Issues can be created from the app, including Azure DevOps work items with
+  state management.
+- Gitea repositories are grouped in the Clone dialog like the other
+  providers.
+
+### Changed
+
+- Undoing the last commit uses a soft reset, so the changes stay staged.
+- Behind segments in the commit graph use the lane color supplied by the
+  graph.
+
+## [2026.9.5] - 2026-09-09
+
+### Changed
+
+- All main views share one page-header layout.
+- The integration board view was refined, and assignees are displayed more
+  compactly.
+
+## [2026.9.4] - 2026-09-08
+
+### Added
+
+- Boards and issues from multiple providers, including moving cards between
+  columns.
+- Pull requests can be created from the app; the dialog loads the repository
+  branches and suggests the current local branch.
+- Repository tabs became a workspace navigation bar.
+- Pull request status is loaded separately and surfaced as badges.
+
+### Changed
+
+- The Review Center table and toolbar adapt to narrow windows.
+
+## [2026.9.3] - 2026-09-08
+
+### Added
+
+- The dashboard offers a list and a card view, and remembers the choice.
+- A notice shows the progress of a running merge.
+
+### Changed
+
+- The line patch dialog was redesigned.
+- Sync colors are defined once as CSS variables.
+
+## [2026.9.2] - 2026-09-07
+
+### Added
+
+- Guided Git bisect with a dedicated dialog for the commit range.
+- The Review Center loads pull requests from the configured integrations,
+  with a detail panel, actions, and search.
+- Conflicts from a pull request merge can be resolved locally; the merge
+  continues automatically and the provider is polled after the push.
+- The dashboard shows pull request badges and links into the Review Center.
+
+### Changed
+
+- Repository management moved into its own dashboard component.
+- Credentials use the Linux keyring.
+
+## [2026.9.1] - 2026-09-01
+
+### Added
+
+- A dialog for initializing a repository.
+- A Merge Branch dialog with a confirmation step.
+- Advanced clone options: shallow, sparse, blobless, and custom flags.
+
+## [2026.8.10] - 2026-08-31
+
+### Changed
+
+- The Clone dialog was redesigned and groups Azure DevOps repositories by
+  project.
+- Tab and dialog close buttons were visually refined.
+
+### Fixed
+
+- The Clone dialog no longer breaks its layout or scrolling on small windows.
+- The loading overlay accounts for the repository tab bar.
+
+## [2026.8.9] - 2026-08-30
+
+### Added
+
+- Pulling histories without a common ancestor is possible as an explicit
+  opt-in.
+
+### Changed
+
+- The AI commit flow was simplified; local models are no longer supported.
+
 ## [2026.8.8] - 2026-08-29
 
 ### Added